Avoid using processId and routingId directly.

atom/browser/api/lib/browser-window.coffee

@@ -40,7 +40,7 @@ BrowserWindow::_init = ->
   # Tell the rpc server that a render view has been deleted and we need to
   # release all objects owned by it.
   @webContents.on 'render-view-deleted', (event, processId, routingId) ->
-    process.emit 'ATOM_BROWSER_RELEASE_RENDER_VIEW', processId, routingId
+    process.emit 'ATOM_BROWSER_RELEASE_RENDER_VIEW', "#{processId}-#{routingId}"
 
 BrowserWindow::toggleDevTools = ->
   if @isDevToolsOpened() then @closeDevTools() else @openDevTools()
@@ -71,17 +71,13 @@ BrowserWindow.getFocusedWindow = ->
   windows = BrowserWindow.getAllWindows()
   return window for window in windows when window.isFocused()
 
-BrowserWindow.fromProcessIdAndRoutingId = (processId, routingId) ->
+BrowserWindow.fromWebContents = (webContents) ->
   windows = BrowserWindow.getAllWindows()
-  return window for window in windows when window.getProcessId() == processId and
+  return window for window in windows when webContents.equal window.webContents
-                                           window.getRoutingId() == routingId
 
-BrowserWindow.fromDevTools = (processId, routingId) ->
+BrowserWindow.fromDevToolsWebContents = (webContents) ->
   windows = BrowserWindow.getAllWindows()
-  for window in windows when window.isDevToolsOpened()
+  return window for window in windows when webContents.equal window.devToolsWebContents
-    devtools = window.getDevTools()
-    return window if devtools.processId == processId and
-                     devtools.routingId == routingId
 
 # Helpers.
 BrowserWindow::loadUrl = -> @webContents.loadUrl.apply @webContents, arguments
@@ -98,9 +94,6 @@ BrowserWindow::stop = -> @webContents.stop()
 BrowserWindow::getRoutingId = -> @webContents.getRoutingId()
 BrowserWindow::getProcessId = -> @webContents.getProcessId()
 BrowserWindow::isCrashed = -> @webContents.isCrashed()
-BrowserWindow::getDevTools = ->
-  processId: @devToolsWebContents.getProcessId()
-  routingId: @devToolsWebContents.getRoutingId()
 BrowserWindow::executeJavaScriptInDevTools = (code) ->
   @devToolsWebContents.executeJavaScript code
 

atom/browser/api/lib/web-contents.coffee

@@ -7,10 +7,14 @@ module.exports.wrap = (webContents) ->
   # webContents is an EventEmitter.
   webContents.__proto__ = EventEmitter.prototype
 
-  # Add the send method.
+  # WebContents::send(channel, args..)
   webContents.send = (args...) ->
     @_send 'ATOM_INTERNAL_MESSAGE', [args...]
 
+  # The processId and routingId and identify a webContents.
+  webContents.getId = -> "#{@getProcessId()}-#{@getRoutingId()}"
+  webContents.equal = (other) -> @getId() is other.getId()
+
   # Dispatch IPC messages to the ipc module.
   webContents.on 'ipc-message', (event, channel, args...) =>
     Object.defineProperty event, 'sender', value: webContents

atom/browser/lib/objects-registry.coffee

@@ -29,13 +29,11 @@ class ObjectsStore
     throw new Error("Invalid key #{id} for ObjectsStore") unless @has id
     @objects[id]
 
-  @forRenderView: (processId, routingId) ->
+  @forRenderView: (key) ->
-    key = "#{processId}_#{routingId}"
     @stores[key] = new ObjectsStore unless @stores[key]?
     @stores[key]
 
-  @releaseForRenderView: (processId, routingId) ->
+  @releaseForRenderView: (key) ->
-    key = "#{processId}_#{routingId}"
     delete @stores[key]
 
 class ObjectsRegistry extends EventEmitter
@@ -52,7 +50,7 @@ class ObjectsRegistry extends EventEmitter
 
   # Register a new object, the object would be kept referenced until you release
   # it explicitly.
-  add: (processId, routingId, obj) ->
+  add: (key, obj) ->
     # Some native objects may already been added to objectsWeakMap, be care not
     # to add it twice.
     @objectsWeakMap.add obj unless v8Util.getHiddenValue obj, 'atomId'
@@ -63,7 +61,7 @@ class ObjectsRegistry extends EventEmitter
     # with the storeId.
     # We use a difference key because the same object can be referenced for
     # multiple times by the same renderer view.
-    store = ObjectsStore.forRenderView processId, routingId
+    store = ObjectsStore.forRenderView key
     storeId = store.add obj
 
     [id, storeId]
@@ -73,12 +71,12 @@ class ObjectsRegistry extends EventEmitter
     @objectsWeakMap.get id
 
   # Remove an object according to its storeId.
-  remove: (processId, routingId, storeId) ->
+  remove: (key, storeId) ->
-    ObjectsStore.forRenderView(processId, routingId).remove storeId
+    ObjectsStore.forRenderView(key).remove storeId
 
   # Clear all references to objects from renderer view.
-  clear: (processId, routingId) ->
+  clear: (key) ->
-    @emit "clear-#{processId}-#{routingId}"
+    @emit "clear-#{key}"
-    ObjectsStore.releaseForRenderView processId, routingId
+    ObjectsStore.releaseForRenderView key
 
 module.exports = new ObjectsRegistry

atom/browser/lib/rpc-server.coffee

@@ -22,9 +22,7 @@ valueToMeta = (sender, value) ->
     # Reference the original value if it's an object, because when it's
     # passed to renderer we would assume the renderer keeps a reference of
     # it.
-    processId = sender.getProcessId()
+    [meta.id, meta.storeId] = objectsRegistry.add sender.getId(), value
-    routingId = sender.getRoutingId()
-    [meta.id, meta.storeId] = objectsRegistry.add processId, routingId, value
 
     meta.members = []
     meta.members.push {name: prop, type: typeof field} for prop, field of value
@@ -40,8 +38,6 @@ errorToMeta = (error) ->
 
 # Convert array of meta data from renderer into array of real values.
 unwrapArgs = (sender, args) ->
-  processId = sender.getProcessId()
-  routingId = sender.getRoutingId()
   metaToValue = (meta) ->
     switch meta.type
       when 'value' then meta.value
@@ -57,7 +53,7 @@ unwrapArgs = (sender, args) ->
         -> returnValue
       when 'function'
         rendererReleased = false
-        objectsRegistry.once "clear-#{processId}-#{routingId}", ->
+        objectsRegistry.once "clear-#{sender.getId()}", ->
           rendererReleased = true
 
         ret = ->
@@ -83,8 +79,8 @@ callFunction = (event, func, caller, args) ->
     event.returnValue = valueToMeta event.sender, ret
 
 # Send by BrowserWindow when its render view is deleted.
-process.on 'ATOM_BROWSER_RELEASE_RENDER_VIEW', (processId, routingId) ->
+process.on 'ATOM_BROWSER_RELEASE_RENDER_VIEW', (id) ->
-  objectsRegistry.clear processId, routingId
+  objectsRegistry.clear id
 
 ipc.on 'ATOM_BROWSER_REQUIRE', (event, module) ->
   try
@@ -101,10 +97,8 @@ ipc.on 'ATOM_BROWSER_GLOBAL', (event, name) ->
 ipc.on 'ATOM_BROWSER_CURRENT_WINDOW', (event) ->
   try
     BrowserWindow = require 'browser-window'
-    processId = event.sender.getProcessId()
+    window = BrowserWindow.fromWebContents event.sender
-    routingId = event.sender.getRoutingId()
+    window = BrowserWindow.fromDevToolsWebContents event.sender unless window?
-    window = BrowserWindow.fromProcessIdAndRoutingId processId, routingId
-    window = BrowserWindow.fromDevTools processId, routingId unless window?
     event.returnValue = valueToMeta event.sender, window
   catch e
     event.returnValue = errorToMeta e
@@ -162,6 +156,4 @@ ipc.on 'ATOM_BROWSER_MEMBER_GET', (event, id, name) ->
     event.returnValue = errorToMeta e
 
 ipc.on 'ATOM_BROWSER_DEREFERENCE', (event, storeId) ->
-  processId = event.sender.getProcessId()
+  objectsRegistry.remove event.sender.getId(), storeId
-  routingId = event.sender.getRoutingId()
-  objectsRegistry.remove processId, routingId, storeId