For desktop tab sharing in mac, activate selected tab

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

 // Copyright 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_controller.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #import "base/mac/bundle_locations.h"
 #include "base/strings/sys_string_conversions.h"
 #import "chrome/browser/ui/cocoa/key_equivalent_constants.h"
 #import "chrome/browser/ui/cocoa/media_picker/desktop_media_picker_item.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_delegate.h"
 #include "grit/components_strings.h"
 #import "third_party/google_toolbox_for_mac/src/AppKit/GTMUILocalizerAndLayoutTweaker.h"
 #import "ui/base/cocoa/flipped_view.h"
 #import "ui/base/cocoa/window_size_constants.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/image/image_skia_util_mac.h"
 
 namespace {
 
 const int kInitialContentWidth = 620;
@@ skipping 190 matching lines @@
 }
 
 - (void)reportResult:(content::DesktopMediaID)sourceID {
   if (doneCallback_.is_null()) {
     return;
   }
 
   sourceID.audio_share = [audioShareCheckbox_ isEnabled] &&
                          [audioShareCheckbox_ state] == NSOnState;
 
+  // If the media source is an tab, activate it.
+  if (sourceID.type == content::DesktopMediaID::TYPE_WEB_CONTENTS) {
+    content::WebContents* tab = content::WebContents::FromRenderFrameHost(
+        content::RenderFrameHost::FromID(
+            sourceID.web_contents_id.render_process_id,
+            sourceID.web_contents_id.main_render_frame_id));
+    if (tab)
+      tab->GetDelegate()->ActivateContents(tab);
+  }
+
   // Notify the |callback_| asynchronously because it may release the
   // controller.
   content::BrowserThread::PostTask(
       content::BrowserThread::UI, FROM_HERE,
       base::Bind(doneCallback_, sourceID));
   doneCallback_.Reset();
 }
 
 - (void)sharePressed:(id)sender {
   NSIndexSet* indexes = [sourceBrowser_ selectionIndexes];
@@ skipping 154 matching lines @@
 - (void)sourceThumbnailChangedAtIndex:(int)index {
   const DesktopMediaList::Source& source = media_list_->GetSource(index);
   NSImage* image = gfx::NSImageFromImageSkia(source.thumbnail);
 
   DesktopMediaPickerItem* item = [items_ objectAtIndex:index];
   [item setImageRepresentation:image];
   [sourceBrowser_ reloadData];
 }
 
 @end  // @interface DesktopMediaPickerController