Flash video doesn't play if opened in background tab

content/browser/web_contents/web_contents_view_aura.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/web_contents/web_contents_view_aura.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/metrics/histogram.h"
@@ skipping 746 matching lines @@
 
   // Overridden from aura::WindowObserver:
 #if defined(OS_WIN)
   // Constrained windows are added as children of the parent's parent's view
   // which may overlap with windowed NPAPI plugins. In that case, tell the RWHV
   // so that it can update the plugins' cutout rects accordingly.
   // Note: this is hard coding how Chrome layer adds its dialogs. Since NPAPI is
   // going to be deprecated in a year, this is ok for now. The test for this is
   // PrintPreviewTest.WindowedNPAPIPluginHidden.
   virtual void OnWindowAdded(aura::Window* new_window) OVERRIDE {
-    if (new_window == view_->window_)
-      return;
+    if (new_window != view_->window_) {
+      // Skip the case when the parent moves to the root window.
+      if (new_window != parent_) {
+        // Observe sibling windows of the WebContents, or children of the root
+        // window.
+        if (new_window->parent() == parent_ ||
+            new_window->parent() == view_->window_->GetRootWindow()) {
+          new_window->AddObserver(this);
+        }
+      }
+    }
 
-    if (new_window == parent_)
-      return;  // This happens if the parent moves to the root window.
-
-    // Observe sibling windows of the WebContents, or children of the root
-    // window.
-    if (new_window->parent() == parent_ ||
-        new_window->parent() == view_->window_->GetRootWindow()) {
-      new_window->AddObserver(this);
+    if (new_window->parent() == parent_) {
       UpdateConstrainedWindows(NULL);
     }
   }
 
   virtual void OnWillRemoveWindow(aura::Window* window) OVERRIDE {
     if (window == view_->window_)
       return;
 
     window->RemoveObserver(this);
     UpdateConstrainedWindows(window);
@@ skipping 1002 matching lines @@
       event.location(),
       gfx::Screen::GetScreenFor(GetNativeView())->GetCursorScreenPoint(),
       ConvertAuraEventFlagsToWebInputEventModifiers(event.flags()));
   if (drag_dest_delegate_)
     drag_dest_delegate_->OnDrop();
   current_drop_data_.reset();
   return current_drag_op_;
 }
 
 }  // namespace content