Load the "preload" script in <webview>

atom/browser/atom_browser_client.cc

@@ -156,6 +156,10 @@ void AtomBrowserClient::AppendExtraCommandLineSwitches(
           info.node_integration ? "true" : "false");
       if (info.plugins)
         command_line->AppendSwitch(switches::kEnablePlugins);
+      if (!info.preload_script.empty())
+        command_line->AppendSwitchPath(
+            switches::kPreloadScript,
+            info.preload_script);
     }
   }
 

atom/browser/lib/guest-view-manager.coffee

@@ -33,7 +33,8 @@ createGuest = (embedder, params) ->
     guestInstanceId: id
     storagePartitionId: params.storagePartitionId
   guestInstances[id] = {guest, embedder}
-  webViewManager.addGuest id, embedder, guest, params.nodeIntegration, params.plugins
+  preload = params.preload ? ''
+  webViewManager.addGuest id, embedder, guest, params.nodeIntegration, params.plugins, preload
 
   # Destroy guest when the embedder is gone.
   embedder.once 'render-view-deleted', ->

atom/browser/web_view/web_view_manager.cc

@@ -7,12 +7,14 @@
 #include "atom/browser/api/atom_api_web_contents.h"
 #include "atom/browser/atom_browser_context.h"
 #include "atom/browser/web_view/web_view_renderer_state.h"
+#include "atom/common/native_mate_converters/gurl_converter.h"
 #include "base/bind.h"
 #include "base/stl_util.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
 #include "native_mate/dictionary.h"
 #include "native_mate/object_template_builder.h"
+#include "net/base/filename_util.h"
 
 #include "atom/common/node_includes.h"
 
@@ -44,12 +46,14 @@ void WebViewManager::AddGuest(int guest_instance_id,
                               content::WebContents* embedder,
                               content::WebContents* web_contents,
                               bool node_integration,
-                              bool plugins) {
+                              bool plugins,
+                              const GURL& preload_url) {
   web_contents_map_[guest_instance_id] = { web_contents, embedder };
 
   WebViewRendererState::WebViewInfo web_view_info = {
     guest_instance_id, node_integration, plugins
   };
+  net::FileURLToFilePath(preload_url, &web_view_info.preload_script);
   content::BrowserThread::PostTask(
       content::BrowserThread::IO,
       FROM_HERE,

atom/browser/web_view/web_view_manager.h

@@ -24,7 +24,8 @@ class WebViewManager : public content::BrowserPluginGuestManager {
                 content::WebContents* embedder,
                 content::WebContents* web_contents,
                 bool node_integration,
-                bool plugins);
+                bool plugins,
+                const GURL& preload_url);
   void RemoveGuest(int guest_instance_id);
 
  protected:

atom/browser/web_view/web_view_renderer_state.h

@@ -9,6 +9,7 @@
 #include <string>
 #include <utility>
 
+#include "base/files/file_path.h"
 #include "base/memory/singleton.h"
 
 namespace atom {
@@ -23,6 +24,7 @@ class WebViewRendererState {
     int guest_instance_id;
     bool node_integration;
     bool plugins;
+    base::FilePath preload_script;
   };
 
   static WebViewRendererState* GetInstance();

atom/common/options_switches.cc

@@ -66,6 +66,9 @@ const char kEnablePlugins[] = "enable-plugins";
 // Instancd ID of guest WebContents.
 const char kGuestInstanceID[] = "guest-instance-id";
 
+// Script that will be loaded by guest WebContents before other scripts.
+const char kPreloadScript[] = "preload-script";
+
 // Web runtime features.
 const char kExperimentalFeatures[]       = "experimental-features";
 const char kExperimentalCanvasFeatures[] = "experimental-canvas-features";

atom/common/options_switches.h

@@ -38,6 +38,7 @@ extern const char kDarkTheme[];
 extern const char kDirectWrite[];
 extern const char kEnablePlugins[];
 extern const char kGuestInstanceID[];
+extern const char kPreloadScript[];
 
 extern const char kExperimentalFeatures[];
 extern const char kExperimentalCanvasFeatures[];

atom/renderer/lib/init.coffee

@@ -31,6 +31,8 @@ for arg in process.argv
     require('web-frame').setName 'ATOM_SHELL_GUEST_WEB_VIEW'
   else if arg.indexOf('--node-integration=') == 0
     nodeIntegration = arg.substr arg.indexOf('=') + 1
+  else if arg.indexOf('--preload-script=') == 0
+    preloadScript = arg.substr arg.indexOf('=') + 1
 
 if location.protocol is 'chrome-devtools:'
   # Override some inspector APIs.
@@ -86,3 +88,6 @@ else
     delete global.process
     delete global.setImmediate
     delete global.clearImmediate
+
+# Load the script specfied by the "preload" attribute.
+require preloadScript if preloadScript