Implement Desktop Media Picker (Mac version) for Desktop Capture API

chrome/browser/ui/cocoa/media_picker/desktop_media_picker_bridge.mm

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "chrome/browser/ui/cocoa/media_picker/desktop_media_picker_bridge.h"
+
+DesktopMediaPickerBridge::DesktopMediaPickerBridge(
+    id<DesktopMediaPickerObserver> observer)
+    : observer_(observer) {
+}
+
+DesktopMediaPickerBridge::~DesktopMediaPickerBridge() {
+}
+
+void DesktopMediaPickerBridge::OnSourceAdded(int index) {
+  [observer_ sourceAddedAtIndex:index];
+}
+
+void DesktopMediaPickerBridge::OnSourceRemoved(int index) {
+  [observer_ sourceRemovedAtIndex:index];
+}
+
+void DesktopMediaPickerBridge::OnSourceNameChanged(int index) {
+  [observer_ sourceNameChangedAtIndex:index];
+}
+
+void DesktopMediaPickerBridge::OnSourceThumbnailChanged(int index) {
+  [observer_ sourceThumbnailChangedAtIndex:index];
+}