Mac low power video: Support child windows, sheets, and transitions

chrome/browser/ui/cocoa/framed_browser_window.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/framed_browser_window.h"
 
 #include <stddef.h>
 
 #include "base/logging.h"
 #include "base/mac/sdk_forward_declarations.h"
@@ skipping 26 matching lines @@
 
 }
 
 @interface FramedBrowserWindow (Private)
 
 - (void)adjustCloseButton:(NSNotification*)notification;
 - (void)adjustMiniaturizeButton:(NSNotification*)notification;
 - (void)adjustZoomButton:(NSNotification*)notification;
 - (void)adjustButton:(NSButton*)button
               ofKind:(NSWindowButton)kind;
+- (void)childWindowsDidChange;
 
 @end
 
 @implementation FramedBrowserWindow
 
 - (void)setStyleMask:(NSUInteger)styleMask {
   if (styleMaskLock_)
     return;
   [super setStyleMask:styleMask];
 }
@@ skipping 295 matching lines @@
 
   ThemedWindowStyle windowStyle = [self themedWindowStyle];
   BOOL incognito = windowStyle & THEMED_INCOGNITO;
 
   if (incognito)
     return [NSColor whiteColor];
   else
     return [NSColor windowFrameTextColor];
 }
 
+- (void)addChildWindow:(NSWindow*)childWindow
+               ordered:(NSWindowOrderingMode)orderingMode {
+  [super addChildWindow:childWindow ordered:orderingMode];
+  [self childWindowsDidChange];
+}
+
+- (void)removeChildWindow:(NSWindow*)childWindow {
+  [super removeChildWindow:childWindow];
+  [self childWindowsDidChange];
+}
+
+- (void)childWindowsDidChange {
+  id delegate = [self delegate];
+  if ([delegate respondsToSelector:@selector(childWindowsDidChange)])
+    [delegate childWindowsDidChange];
+}
+
 @end