Refine: make desktop-capturer as a renderer module.

atom/browser/lib/desktop-capturer.coffee

@@ -0,0 +1,42 @@
+ipc = require 'ipc'
+BrowserWindow = require 'browser-window'
+EventEmitter = require('events').EventEmitter
+
+# The browser module manages all desktop-capturer moduels in renderer process.
+desktopCapturer = process.atomBinding('desktop_capturer').desktopCapturer
+desktopCapturer.__proto__ = EventEmitter.prototype
+
+getWebContentsFromId = (id) ->
+  windows = BrowserWindow.getAllWindows()
+  return window.webContents for window in windows when window.webContents?.getId() == id
+
+# The set for tracking id of webContents.
+webContentsIds = new Set
+
+stopDesktopCapture = (id) ->
+  webContentsIds.delete id
+  if webContentsIds.size is 0
+    desktopCapturer.stopUpdating()
+
+ipc.on 'ATOM_BROWSER_DESKTOP_CAPTURER_REQUIRED', (event) ->
+  id = event.sender.getId()
+  # Remove the tracked webContents when it is destroyed.
+  getWebContentsFromId(id).on 'destroyed', ()->
+    stopDesktopCapture id
+  event.returnValue = 'done'
+
+# Handle `desktopCapturer.startUpdating` API.
+ipc.on 'ATOM_BROWSER_DESKTOP_CAPTURER_START_UPDATING', (event, args) ->
+  id = event.sender.getId()
+  webContentsIds.add id
+  desktopCapturer.startUpdating args
+
+# Handle `desktopCapturer.stopUpdating` API.
+ipc.on 'ATOM_BROWSER_DESKTOP_CAPTURER_STOP_UPDATING', (event) ->
+  stopDesktopCapture event.sender.getId()
+
+for event_name in ['source-added', 'source-removed', 'source-name-changed', "source-thumbnail-changed"]
+  do (event_name) ->
+    desktopCapturer.on event_name, (event, source) ->
+      webContentsIds.forEach (id) ->
+        getWebContentsFromId(id).send event_name, { id: source.id, name: source.name, dataUrl: source.thumbnail.toDataUrl() }

atom/browser/lib/init.coffee

@@ -92,6 +92,9 @@ app.setAppPath packagePath
 # Load the chrome extension support.
 require './chrome-extension'
 
+# Load internal desktop-capturer module.
+require './desktop-capturer'
+
 # Set main startup script of the app.
 mainStartupScript = packageJson.main or 'index.js'