From 380de24f2ea0c8b708e5517ab8fc3c58362e4a92 Mon Sep 17 00:00:00 2001
From: Cheng Zhao <zcbenz@gmail.com>
Date: Wed, 22 Oct 2014 22:55:13 +0800
Subject: [PATCH] Add code to register <webview> tag

---
 atom.gyp                                  |   5 +
 atom/browser/atom_browser_context.cc      |   7 +
 atom/browser/atom_browser_context.h       |   7 +-
 atom/browser/default_app/index.html       |   2 +
 atom/browser/web_view/web_view_guest.cc   |  11 +
 atom/browser/web_view/web_view_guest.h    |  19 +
 atom/browser/web_view/web_view_manager.cc |  31 ++
 atom/browser/web_view/web_view_manager.h  |  35 ++
 atom/renderer/lib/init.coffee             |   2 +
 atom/renderer/lib/webview.coffee          | 531 ++++++++++++++++++++++
 10 files changed, 649 insertions(+), 1 deletion(-)
 create mode 100644 atom/browser/web_view/web_view_guest.cc
 create mode 100644 atom/browser/web_view/web_view_guest.h
 create mode 100644 atom/browser/web_view/web_view_manager.cc
 create mode 100644 atom/browser/web_view/web_view_manager.h
 create mode 100644 atom/renderer/lib/webview.coffee

diff --git a/atom.gyp b/atom.gyp
index 7b439cbbfe1..0f69b18f41e 100644
--- a/atom.gyp
+++ b/atom.gyp
@@ -44,6 +44,7 @@
       'atom/renderer/lib/init.coffee',
       'atom/renderer/lib/inspector.coffee',
       'atom/renderer/lib/override.coffee',
+      'atom/renderer/lib/webview.coffee',
       'atom/renderer/api/lib/ipc.coffee',
       'atom/renderer/api/lib/remote.coffee',
       'atom/renderer/api/lib/web-view.coffee',
@@ -178,6 +179,10 @@
       'atom/browser/ui/win/notify_icon.h',
       'atom/browser/ui/x/x_window_utils.cc',
       'atom/browser/ui/x/x_window_utils.h',
+      'atom/browser/web_view/web_view_guest.cc',
+      'atom/browser/web_view/web_view_guest.h',
+      'atom/browser/web_view/web_view_manager.cc',
+      'atom/browser/web_view/web_view_manager.h',
       'atom/browser/window_list.cc',
       'atom/browser/window_list.h',
       'atom/browser/window_list_observer.h',
diff --git a/atom/browser/atom_browser_context.cc b/atom/browser/atom_browser_context.cc
index 4c4ac3d384c..ae3c6f70ae0 100644
--- a/atom/browser/atom_browser_context.cc
+++ b/atom/browser/atom_browser_context.cc
@@ -7,6 +7,7 @@
 #include "atom/browser/atom_browser_main_parts.h"
 #include "atom/browser/net/atom_url_request_job_factory.h"
 #include "atom/browser/net/asar/asar_protocol_handler.h"
+#include "atom/browser/web_view/web_view_manager.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/worker_pool.h"
 #include "chrome/browser/browser_process.h"
@@ -68,6 +69,12 @@ net::URLRequestJobFactory* AtomBrowserContext::CreateURLRequestJobFactory(
   return top_job_factory.release();
 }
 
+content::BrowserPluginGuestManager* AtomBrowserContext::GetGuestManager() {
+  if (!guest_manager_)
+    guest_manager_.reset(new WebViewManager(this));
+  return guest_manager_.get();
+}
+
 // static
 AtomBrowserContext* AtomBrowserContext::Get() {
   return static_cast<AtomBrowserContext*>(
diff --git a/atom/browser/atom_browser_context.h b/atom/browser/atom_browser_context.h
index 95db71ff699..71a023cea5f 100644
--- a/atom/browser/atom_browser_context.h
+++ b/atom/browser/atom_browser_context.h
@@ -12,6 +12,7 @@ class BrowserProcess;
 namespace atom {
 
 class AtomURLRequestJobFactory;
+class WebViewManager;
 
 class AtomBrowserContext : public brightray::BrowserContext {
  public:
@@ -27,11 +28,15 @@ class AtomBrowserContext : public brightray::BrowserContext {
   // brightray::URLRequestContextGetter::Delegate:
   virtual net::URLRequestJobFactory* CreateURLRequestJobFactory(
       content::ProtocolHandlerMap* handlers,
-      content::URLRequestInterceptorScopedVector* interceptors) OVERRIDE;
+      content::URLRequestInterceptorScopedVector* interceptors) override;
+
+  // content::BrowserContext:
+  virtual content::BrowserPluginGuestManager* GetGuestManager() override;
 
  private:
   // A fake BrowserProcess object that used to feed the source code from chrome.
   scoped_ptr<BrowserProcess> fake_browser_process_;
+  scoped_ptr<WebViewManager> guest_manager_;
 
   AtomURLRequestJobFactory* job_factory_;  // Weak reference.
 
diff --git a/atom/browser/default_app/index.html b/atom/browser/default_app/index.html
index 83b5122782f..810f11f1847 100644
--- a/atom/browser/default_app/index.html
+++ b/atom/browser/default_app/index.html
@@ -56,6 +56,8 @@
   </style>
 </head>
 <body>
+  <browser-plugin type="application/browser-plugin"></browser-plugin>
+
   <script>
     var execPath = require('remote').process.execPath;
     var command = execPath + ' path-to-your-app';
diff --git a/atom/browser/web_view/web_view_guest.cc b/atom/browser/web_view/web_view_guest.cc
new file mode 100644
index 00000000000..37c14f72695
--- /dev/null
+++ b/atom/browser/web_view/web_view_guest.cc
@@ -0,0 +1,11 @@
+// Copyright (c) 2014 GitHub, Inc. All rights reserved.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#include "atom/browser/web_view/web_view_guest.h"
+
+namespace atom {
+
+
+
+}  // namespace atom
diff --git a/atom/browser/web_view/web_view_guest.h b/atom/browser/web_view/web_view_guest.h
new file mode 100644
index 00000000000..9696eca595f
--- /dev/null
+++ b/atom/browser/web_view/web_view_guest.h
@@ -0,0 +1,19 @@
+// Copyright (c) 2014 GitHub, Inc. All rights reserved.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_BROWSER_WEB_VIEW_WEB_VIEW_GUEST_H_
+#define ATOM_BROWSER_WEB_VIEW_WEB_VIEW_GUEST_H_
+
+namespace atom {
+
+// A WebViewGuest provides the browser-side implementation of the <webview> API
+// and manages the dispatch of <webview> extension events. WebViewGuest is
+// created on attachment. That is, when a guest WebContents is associated with
+// a particular embedder WebContents. This happens on either initial navigation
+// or through the use of the New Window API, when a new window is attached to
+// a particular <webview>.
+
+}  // namespace atom
+
+#endif  // ATOM_BROWSER_WEB_VIEW_WEB_VIEW_GUEST_H_
diff --git a/atom/browser/web_view/web_view_manager.cc b/atom/browser/web_view/web_view_manager.cc
new file mode 100644
index 00000000000..48e1b1fdf56
--- /dev/null
+++ b/atom/browser/web_view/web_view_manager.cc
@@ -0,0 +1,31 @@
+// Copyright (c) 2014 GitHub, Inc. All rights reserved.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#include "atom/browser/web_view/web_view_manager.h"
+
+#include "base/logging.h"
+
+namespace atom {
+
+WebViewManager::WebViewManager(content::BrowserContext* context) {
+}
+
+WebViewManager::~WebViewManager() {
+}
+
+void WebViewManager::MaybeGetGuestByInstanceIDOrKill(
+    int guest_instance_id,
+    int embedder_render_process_id,
+    const GuestByInstanceIDCallback& callback) {
+  LOG(ERROR) << "MaybeGetGuestByInstanceIDOrKill";
+  callback.Run(nullptr);
+}
+
+bool WebViewManager::ForEachGuest(content::WebContents* embedder_web_contents,
+                                  const GuestCallback& callback) {
+  LOG(ERROR) << "ForEachGuest";
+  return false;
+}
+
+}  // namespace atom
diff --git a/atom/browser/web_view/web_view_manager.h b/atom/browser/web_view/web_view_manager.h
new file mode 100644
index 00000000000..25bc9bd3965
--- /dev/null
+++ b/atom/browser/web_view/web_view_manager.h
@@ -0,0 +1,35 @@
+// Copyright (c) 2014 GitHub, Inc. All rights reserved.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_BROWSER_WEB_VIEW_WEB_VIEW_MANAGER_H_
+#define ATOM_BROWSER_WEB_VIEW_WEB_VIEW_MANAGER_H_
+
+#include "content/public/browser/browser_plugin_guest_manager.h"
+
+namespace content {
+class BrowserContext;
+}
+
+namespace atom {
+
+class WebViewManager : public content::BrowserPluginGuestManager {
+ public:
+  explicit WebViewManager(content::BrowserContext* context);
+  virtual ~WebViewManager();
+
+  // content::BrowserPluginGuestManager:
+  virtual void MaybeGetGuestByInstanceIDOrKill(
+      int guest_instance_id,
+      int embedder_render_process_id,
+      const GuestByInstanceIDCallback& callback) override;
+  virtual bool ForEachGuest(content::WebContents* embedder_web_contents,
+                            const GuestCallback& callback) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(WebViewManager);
+};
+
+}  // namespace atom
+
+#endif  // ATOM_BROWSER_WEB_VIEW_WEB_VIEW_MANAGER_H_
diff --git a/atom/renderer/lib/init.coffee b/atom/renderer/lib/init.coffee
index ac11ac0d341..c39d88dd9bd 100644
--- a/atom/renderer/lib/init.coffee
+++ b/atom/renderer/lib/init.coffee
@@ -56,3 +56,5 @@ else if location.protocol is 'chrome-extension:'
 else
   # Override default web functions.
   require path.join(__dirname, 'override')
+  # Load webview tag implementation.
+  require path.join(__dirname, 'webview')
diff --git a/atom/renderer/lib/webview.coffee b/atom/renderer/lib/webview.coffee
new file mode 100644
index 00000000000..0e72d759466
--- /dev/null
+++ b/atom/renderer/lib/webview.coffee
@@ -0,0 +1,531 @@
+v8Util = process.atomBinding 'v8_util'
+webView = require 'web-view'
+
+# ID generator.
+nextId = 1
+getNextId = -> nextId++
+
+# Attributes.
+WEB_VIEW_ATTRIBUTE_ALLOWTRANSPARENCY = 'allowtransparency'
+WEB_VIEW_ATTRIBUTE_AUTOSIZE = 'autosize'
+WEB_VIEW_ATTRIBUTE_MAXHEIGHT = 'maxheight'
+WEB_VIEW_ATTRIBUTE_MAXWIDTH = 'maxwidth'
+WEB_VIEW_ATTRIBUTE_MINHEIGHT = 'minheight'
+WEB_VIEW_ATTRIBUTE_MINWIDTH = 'minwidth'
+WEB_VIEW_ATTRIBUTE_PARTITION = 'partition'
+AUTO_SIZE_ATTRIBUTES = [
+  WEB_VIEW_ATTRIBUTE_AUTOSIZE,
+  WEB_VIEW_ATTRIBUTE_MAXHEIGHT,
+  WEB_VIEW_ATTRIBUTE_MAXWIDTH,
+  WEB_VIEW_ATTRIBUTE_MINHEIGHT,
+  WEB_VIEW_ATTRIBUTE_MINWIDTH,
+]
+
+# Error messages.
+ERROR_MSG_ALREADY_NAVIGATED =
+    'The object has already navigated, so its partition cannot be changed.'
+ERROR_MSG_CANNOT_INJECT_SCRIPT = '<webview>: ' +
+    'Script cannot be injected into content until the page has loaded.'
+ERROR_MSG_CONTENTWINDOW_NOT_AVAILABLE = '<webview>: ' +
+    'contentWindow is not available at this time. It will become available ' +
+    'when the page has finished loading.'
+ERROR_MSG_INVALID_PARTITION_ATTRIBUTE = 'Invalid partition attribute.'
+
+# Represents the state of the storage partition.
+class Partition
+  constructor: ->
+    @validPartitionId = true
+    @persistStorage = false
+    @storagePartitionId = ''
+
+  toAttribute: ->
+    return '' unless @validPartitionId
+    (@persistStorage ? 'persist:' : '') + @storagePartitionId
+
+  fromAttribute: (value, hasNavigated) ->
+    result = {}
+    if hasNavigated
+      result.error = ERROR_MSG_ALREADY_NAVIGATED
+      return result
+    value ?= ''
+
+    LEN = 'persist:'.length
+    if value.substr(0, LEN) == 'persist:'
+      value = value.substr LEN
+      unless value
+        @validPartitionId = false
+        result.error = ERROR_MSG_INVALID_PARTITION_ATTRIBUTE
+        return result
+      @persistStorage = true
+    else
+      @persistStorage = false
+
+    @storagePartitionId = value
+    result
+
+# Represents the internal state of the WebView node.
+class WebView
+  constructor: (@webviewNode) ->
+    v8Util.setHiddenValue webviewNode, 'internal', this
+    @attached = false
+    @pendingGuestCreation = false
+    @elementAttached = false
+
+    @beforeFirstNavigation = true
+    @contentWindow = null
+    @validPartitionId = true
+    # Used to save some state upon deferred attachment.
+    # If <object> bindings is not available, we defer attachment.
+    # This state contains whether or not the attachment request was for
+    # newwindow.
+    @deferredAttachState = null
+
+    # on* Event handlers.
+    @on = {}
+
+    @browserPluginNode = @createBrowserPluginNode()
+    shadowRoot = @webviewNode.createShadowRoot()
+    @partition = new Partition()
+
+    @setupWebViewSrcAttributeMutationObserver()
+    @setupFocusPropagation()
+    @setupWebviewNodeProperties()
+
+    @viewInstanceId = getNextId()
+
+    shadowRoot.appendChild @browserPluginNode
+
+  createBrowserPluginNode: ->
+    # We create BrowserPlugin as a custom element in order to observe changes
+    # to attributes synchronously.
+    browserPluginNode = new WebView.BrowserPlugin()
+    v8Util.setHiddenValue browserPluginNode, 'internal', this
+    browserPluginNode
+
+  getGuestInstanceId: ->
+    @guestInstanceId
+
+  # Resets some state upon reattaching <webview> element to the DOM.
+  reset: ->
+    # If guestInstanceId is defined then the <webview> has navigated and has
+    # already picked up a partition ID. Thus, we need to reset the initialization
+    # state. However, it may be the case that beforeFirstNavigation is false BUT
+    # guestInstanceId has yet to be initialized. This means that we have not
+    # heard back from createGuest yet. We will not reset the flag in this case so
+    # that we don't end up allocating a second guest.
+    if @guestInstanceId
+      # FIXME
+      # GuestViewInternal.destroyGuest @guestInstanceId
+      @guestInstanceId = undefined
+      @beforeFirstNavigation = true
+      @validPartitionId = true
+      @partition.validPartitionId = true
+      @contentWindow = null
+    @internalInstanceId = 0
+
+  # Sets the <webview>.request property.
+  setRequestPropertyOnWebViewNode: (request) ->
+    Object.defineProperty @webviewNode, 'request', value: request, enumerable: true
+
+  setupFocusPropagation: ->
+    unless @webviewNode.hasAttribute 'tabIndex'
+      # <webview> needs a tabIndex in order to be focusable.
+      # TODO(fsamuel): It would be nice to avoid exposing a tabIndex attribute
+      # to allow <webview> to be focusable.
+      # See http://crbug.com/231664.
+      @webviewNode.setAttribute 'tabIndex', -1
+    @webviewNode.addEventListener 'focus', (e) =>
+      # Focus the BrowserPlugin when the <webview> takes focus.
+      @browserPluginNode.focus()
+    @webviewNode.addEventListener 'blur', (e) =>
+      # Blur the BrowserPlugin when the <webview> loses focus.
+      @browserPluginNode.blur()
+
+  # Validation helper function for executeScript() and insertCSS().
+  validateExecuteCodeCall: ->
+    throw new Error(ERROR_MSG_CANNOT_INJECT_SCRIPT) unless @guestInstanceId
+
+  setupAutoSizeProperties: ->
+    for attributeName in AUTO_SIZE_ATTRIBUTES
+      this[attributeName] = @webviewNode.getAttribute attributeName
+      Object.defineProperty @webviewNode, attributeName,
+        get: => this[attributeName]
+        set: (value) => @webviewNode.setAttribute attributeName, value
+        enumerable: true
+
+  setupWebviewNodeProperties: ->
+    @setupAutoSizeProperties()
+
+    Object.defineProperty @webviewNode, WEB_VIEW_ATTRIBUTE_ALLOWTRANSPARENCY,
+      get: => @allowtransparency
+      set: (value) =>
+        @webviewNode.setAttribute WEB_VIEW_ATTRIBUTE_ALLOWTRANSPARENCY, value
+      enumerable: true
+
+    # We cannot use {writable: true} property descriptor because we want a
+    # dynamic getter value.
+    Object.defineProperty @webviewNode, 'contentWindow',
+      get: =>
+        return @contentWindow if @contentWindow?
+        window.console.error ERROR_MSG_CONTENTWINDOW_NOT_AVAILABLE
+      # No setter.
+      enumerable: true
+
+    Object.defineProperty @webviewNode, 'name',
+      get: => @name
+      set: (value) => @webviewNode.setAttribute 'name', value
+      enumerable: true
+
+    Object.defineProperty @webviewNode, 'partition',
+      get: => @partition.toAttribute()
+      set: (value) =>
+        result = @partition.fromAttribute value, @hasNavigated()
+        throw result.error if result.error?
+        @webviewNode.setAttribute 'partition', value
+      enumerable: true
+
+    @src = @webviewNode.getAttribute 'src'
+    Object.defineProperty @webviewNode, 'src',
+      get: => @src
+      set: (value) => @webviewNode.setAttribute 'src', value
+      # No setter.
+      enumerable: true
+
+  # The purpose of this mutation observer is to catch assignment to the src
+  # attribute without any changes to its value. This is useful in the case
+  # where the webview guest has crashed and navigating to the same address
+  # spawns off a new process.
+  setupWebViewSrcAttributeMutationObserver: ->
+    @srcAndPartitionObserver = new MutationObserver (mutations) =>
+      for mutation in mutations
+        oldValue = mutation.oldValue
+        newValue = @webviewNode.getAttribute mutation.attributeName
+        return if oldValue isnt newValue
+        @handleWebviewAttributeMutation mutation.attributeName, oldValue, newValue
+    params =
+      attributes: true,
+      attributeOldValue: true,
+      attributeFilter: ['src', 'partition']
+    @srcAndPartitionObserver.observe @webviewNode, params
+
+  # This observer monitors mutations to attributes of the <webview> and
+  # updates the BrowserPlugin properties accordingly. In turn, updating
+  # a BrowserPlugin property will update the corresponding BrowserPlugin
+  # attribute, if necessary. See BrowserPlugin::UpdateDOMAttribute for more
+  # details.
+  handleWebviewAttributeMutation: (name, oldValue, newValue) ->
+    if name in AUTO_SIZE_ATTRIBUTES
+      this[name] = newValue
+      return unless @guestInstanceId
+      # Convert autosize attribute to boolean.
+      autosize = @webviewNode.hasAttribute WEB_VIEW_ATTRIBUTE_AUTOSIZE
+      # FIXME
+      # GuestViewInternal.setAutoSize @guestInstanceId,
+      #   enableAutoSize: autosize,
+      #   min:
+      #     width: parseInt @minwidth ? 0
+      #     height: parseInt @minheight ? 0
+      #   max:
+      #     width: parseInt @maxwidth ? 0
+      #     height: parseInt @maxheight ? 0
+    else if name is WEB_VIEW_ATTRIBUTE_ALLOWTRANSPARENCY
+      # We treat null attribute (attribute removed) and the empty string as
+      # one case.
+      oldValue ?= ''
+      newValue ?= ''
+
+      return if oldValue is newValue
+      @allowtransparency = newValue != ''
+
+      return unless @guestInstanceId
+
+      # FIXME
+      # WebViewInternal.setAllowTransparency @guestInstanceId, @allowtransparency
+    else if name is 'name'
+      # We treat null attribute (attribute removed) and the empty string as
+      # one case.
+      oldValue ?= ''
+      newValue ?= ''
+
+      return if oldValue is newValue
+      @name = newValue
+
+      return unless @guestInstanceId
+
+      # FIXME
+      # WebViewInternal.setName @guestInstanceId, newValue
+    else if name is 'src'
+      # We treat null attribute (attribute removed) and the empty string as
+      # one case.
+      oldValue ?= ''
+      newValue ?= ''
+      # Once we have navigated, we don't allow clearing the src attribute.
+      # Once <webview> enters a navigated state, it cannot be return back to a
+      # placeholder state.
+      if newValue == '' and oldValue != ''
+        # src attribute changes normally initiate a navigation. We suppress
+        # the next src attribute handler call to avoid reloading the page
+        # on every guest-initiated navigation.
+        @ignoreNextSrcAttributeChange = true
+        @webviewNode.setAttribute 'src', oldValue
+      @src = newValue
+      if @ignoreNextSrcAttributeChange
+        # Don't allow the src mutation observer to see this change.
+        @srcAndPartitionObserver.takeRecords()
+        @ignoreNextSrcAttributeChange = false
+        return
+      result = {}
+      @parseSrcAttribute result
+
+      throw result.error if result.error?
+    else if name is 'partition'
+      # Note that throwing error here won't synchronously propagate.
+      @partition.fromAttribute newValue, @hasNavigated()
+
+  handleBrowserPluginAttributeMutation: (name, oldValue, newValue) ->
+    if name is 'internalinstanceid' and !oldValue and !!newValue
+      @browserPluginNode.removeAttribute 'internalinstanceid'
+      @internalInstanceId = parseInt newValue
+
+      if !!@guestInstanceId and @guestInstanceId != 0
+        isNewWindow = if @deferredAttachState then @deferredAttachState.isNewWindow else false
+        params = @buildAttachParams isNewWindow
+        # FIXME
+        # guestViewInternalNatives.AttachGuest
+        #   @internalInstanceId,
+        #   @guestInstanceId,
+        #   params,
+        #   (w) => @contentWindow = w
+
+  onSizeChanged: (webViewEvent) ->
+    newWidth = webViewEvent.newWidth
+    newHeight = webViewEvent.newHeight
+
+    node = @webviewNode
+
+    width = node.offsetWidth
+    height = node.offsetHeight
+
+    # Check the current bounds to make sure we do not resize <webview>
+    # outside of current constraints.
+    if node.hasAttribute(WEB_VIEW_ATTRIBUTE_MAXWIDTH) and
+       node[WEB_VIEW_ATTRIBUTE_MAXWIDTH]
+      maxWidth = node[WEB_VIEW_ATTRIBUTE_MAXWIDTH]
+    else
+      maxWidth = width
+
+    if node.hasAttribute(WEB_VIEW_ATTRIBUTE_MINWIDTH) and
+       node[WEB_VIEW_ATTRIBUTE_MINWIDTH]
+      minWidth = node[WEB_VIEW_ATTRIBUTE_MINWIDTH]
+    else
+      minWidth = width
+    minWidth = maxWidth if minWidth > maxWidth
+
+    if node.hasAttribute(WEB_VIEW_ATTRIBUTE_MAXHEIGHT) and
+       node[WEB_VIEW_ATTRIBUTE_MAXHEIGHT]
+      maxHeight = node[WEB_VIEW_ATTRIBUTE_MAXHEIGHT]
+    else
+      maxHeight = height
+
+    if node.hasAttribute(WEB_VIEW_ATTRIBUTE_MINHEIGHT) and
+       node[WEB_VIEW_ATTRIBUTE_MINHEIGHT]
+      minHeight = node[WEB_VIEW_ATTRIBUTE_MINHEIGHT]
+    else
+      minHeight = height
+    minHeight = maxHeight if minHeight > maxHeight
+
+    if not @webviewNode.hasAttribute WEB_VIEW_ATTRIBUTE_AUTOSIZE or
+       (newWidth >= minWidth and
+        newWidth <= maxWidth and
+        newHeight >= minHeight and
+        newHeight <= maxHeight)
+      node.style.width = newWidth + 'px'
+      node.style.height = newHeight + 'px'
+      # Only fire the DOM event if the size of the <webview> has actually
+      # changed.
+      @dispatchEvent webViewEvent
+
+  # Returns if <object> is in the render tree.
+  isPluginInRenderTree: ->
+    !!@internalInstanceId && @internalInstanceId != 0
+
+  hasNavigated: ->
+    not @beforeFirstNavigation
+
+  parseSrcAttribute: (result) ->
+    unless @partition.validPartitionId
+      result.error = ERROR_MSG_INVALID_PARTITION_ATTRIBUTE
+      return
+    @src = @webviewNode.getAttribute 'src'
+
+    return unless @src
+
+    unless @guestInstanceId?
+      if @beforeFirstNavigation
+        @beforeFirstNavigation = false
+        @createGuest()
+      return
+
+    # Navigate to |this.src|.
+    # FIXME
+    # WebViewInternal.navigate @guestInstanceId, @src
+
+  parseAttributes: ->
+    return unless @elementAttached
+    hasNavigated = @hasNavigated()
+    attributeValue = @webviewNode.getAttribute 'partition'
+    result = @partition.fromAttribute attributeValue, hasNavigated
+    @parseSrcAttribute result
+
+  createGuest: ->
+    return if @pendingGuestCreation?
+    storagePartitionId =
+      @webviewNode.getAttribute(WEB_VIEW_ATTRIBUTE_PARTITION) or
+      @webviewNode[WEB_VIEW_ATTRIBUTE_PARTITION]
+    params = storagePartitionId: storagePartitionId
+    # FIXME
+    # GuestViewInternal.createGuest 'webview', params, (guestInstanceId) =>
+    #   @pendingGuestCreation = false
+    #   unless @elementAttached
+    #     GuestViewInternal.destroyGuest guestInstanceId
+    #     return
+    #   @attachWindow guestInstanceId, false
+    @pendingGuestCreation = true
+
+  onFrameNameChanged: (name) ->
+    @name ?= ''
+    if @name is ''
+      @webviewNode.removeAttribute 'name'
+    else
+      @webviewNode.setAttribute 'name', @name
+
+  @dispatchEvent = (webViewEvent) ->
+    @webviewNode.dispatchEvent webViewEvent
+
+  # Adds an 'on<event>' property on the webview, which can be used to set/unset
+  # an event handler.
+  setupEventProperty: (eventName) ->
+    propertyName = 'on' + eventName.toLowerCase()
+    Object.defineProperty @webviewNode, propertyName,
+      get: => @on[propertyName]
+      set: (value) =>
+        if @on[propertyName]
+          @webviewNode.removeEventListener eventName, @on[propertyName]
+        @on[propertyName] = value
+        if value
+          @webviewNode.addEventListener eventName, value
+      enumerable: true
+
+  # Updates state upon loadcommit.
+  onLoadCommit: (@baseUrlForDataUrl, @currentEntryIndex, @entryCount, @processId, url, isTopLevel) ->
+    oldValue = @webviewNode.getAttribute 'src'
+    newValue = url
+    if isTopLevel and (oldValue != newValue)
+      # Touching the src attribute triggers a navigation. To avoid
+      # triggering a page reload on every guest-initiated navigation,
+      # we use the flag ignoreNextSrcAttributeChange here.
+      this.ignoreNextSrcAttributeChange = true
+      this.webviewNode.setAttribute 'src', newValue
+
+  onAttach: (storagePartitionId) ->
+    @webviewNode.setAttribute 'partition', storagePartitionId
+    @partition.fromAttribute storagePartitionId, this.hasNavigated()
+
+  buildAttachParams: (isNewWindow) ->
+    allowtransparency: @allowtransparency || false
+    autosize: @webviewNode.hasAttribute WEB_VIEW_ATTRIBUTE_AUTOSIZE
+    instanceId: @viewInstanceId
+    maxheight: parseInt @maxheight || 0
+    maxwidth: parseInt @maxwidth || 0
+    minheight: parseInt @minheight || 0
+    minwidth: parseInt @minwidth || 0
+    name: @name
+    # We don't need to navigate new window from here.
+    src: isNewWindow ? undefined : @src
+    # If we have a partition from the opener, that will also be already
+    # set via this.onAttach().
+    storagePartitionId: @partition.toAttribute()
+    userAgentOverride: @userAgentOverride
+
+  attachWindow: (guestInstanceId, isNewWindow) ->
+    @guestInstanceId = guestInstanceId
+    params = @buildAttachParams isNewWindow
+
+    unless @isPluginInRenderTree()
+      @deferredAttachState =  isNewWindow: isNewWindow
+      return true
+
+    @deferredAttachState = null
+    # FIXME
+    # guestViewInternalNatives.AttachGuest @internalInstanceId, @guestInstanceId, params, (w) => @contentWindow = w
+
+# Registers browser plugin <object> custom element.
+registerBrowserPluginElement = ->
+  proto = Object.create HTMLObjectElement.prototype
+
+  proto.createdCallback = ->
+    @setAttribute 'type', 'application/browser-plugin'
+    @setAttribute 'id', 'browser-plugin-' + getNextId()
+    # The <object> node fills in the <webview> container.
+    @style.width = '100%'
+    @style.height = '100%'
+
+  proto.attributeChangedCallback = (name, oldValue, newValue) ->
+    internal = v8Util.getHiddenValue 'internal'
+    return unless internal
+    internal.handleBrowserPluginAttributeMutation name, oldValue, newValue
+
+  proto.attachedCallback = ->
+    # Load the plugin immediately.
+    unused = this.nonExistentAttribute
+
+  WebView.BrowserPlugin = webView.registerEmbedderCustomElement 'browserplugin',
+    extends: 'object', prototype: proto
+
+  delete proto.createdCallback
+  delete proto.attachedCallback
+  delete proto.detachedCallback
+  delete proto.attributeChangedCallback
+
+# Registers <webview> custom element.
+registerWebViewElement = ->
+  proto = Object.create HTMLObjectElement.prototype
+
+  proto.createdCallback = ->
+    new WebView(this)
+
+  proto.attributeChangedCallback = (name, oldValue, newValue) ->
+    internal = v8Util.getHiddenValue 'internal'
+    return unless internal
+    internal.handleWebviewAttributeMutation name, oldValue, newValue
+
+  proto.detachedCallback = ->
+    internal = v8Util.getHiddenValue 'internal'
+    return unless internal
+    internal.elementAttached = false
+    internal.reset()
+
+  proto.attachedCallback = ->
+    internal = v8Util.getHiddenValue 'internal'
+    return unless internal
+    unless internal.elementAttached
+      internal.elementAttached = true
+      internal.parseAttributes()
+
+  window.WebView = webView.registerEmbedderCustomElement 'webview',
+    prototype: proto
+
+  # Delete the callbacks so developers cannot call them and produce unexpected
+  # behavior.
+  delete proto.createdCallback
+  delete proto.attachedCallback
+  delete proto.detachedCallback
+  delete proto.attributeChangedCallback
+
+useCapture = true
+listener = (event) ->
+  return if document.readyState == 'loading'
+  registerBrowserPluginElement()
+  registerWebViewElement()
+  window.removeEventListener event.type, listener, useCapture
+window.addEventListener 'readystatechange', listener, true