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

chrome/browser/ui/cocoa/framed_browser_window.mm

Index: chrome/browser/ui/cocoa/framed_browser_window.mm
diff --git a/chrome/browser/ui/cocoa/framed_browser_window.mm b/chrome/browser/ui/cocoa/framed_browser_window.mm
index 4dd768595bd8661538b811ed36880ccf4af656ca..c9e337c376d2299a39397e399978c44c116d9c00 100644
--- a/chrome/browser/ui/cocoa/framed_browser_window.mm
+++ b/chrome/browser/ui/cocoa/framed_browser_window.mm
@@ -44,6 +44,7 @@ - (void)adjustMiniaturizeButton:(NSNotification*)notification;
 - (void)adjustZoomButton:(NSNotification*)notification;
 - (void)adjustButton:(NSButton*)button
               ofKind:(NSWindowButton)kind;
+- (void)childWindowsDidChange;
 
 @end
 
@@ -359,4 +360,21 @@ - (NSColor*)titleColor {
     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