[Mac] Use NSTitlebarAccessoryViewController to implement colored app window frames.

chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm

Index: chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm b/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
index cacab46219f9aa2b960632eea8f5d4e513415161..aaea1451b3ba4e9379a670d6c34b9c3320831961 100644
--- a/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
@@ -162,6 +162,11 @@ std::vector<gfx::Rect> CalculateNonDraggableRegions(
     appWindow_->WindowDidEnterFullscreen();
 }
 
+- (void)windowWillExitFullScreen:(NSNotification*)notification {
+  if (appWindow_)
+    appWindow_->WindowWillExitFullscreen();
+}
+
 - (void)windowDidExitFullScreen:(NSNotification*)notification {
   if (appWindow_)
     appWindow_->WindowDidExitFullscreen();
@@ -236,6 +241,10 @@ std::vector<gfx::Rect> CalculateNonDraggableRegions(
 
 @end
 
+@interface NSViewController ()
+@property NSInteger layoutAttribute;
+@end
+
 // TODO(jamescook): Should these be AppNSWindow to match AppWindow?
 // http://crbug.com/344082
 @interface ShellNSWindow : ChromeEventProcessingWindow
@@ -295,6 +304,31 @@ std::vector<gfx::Rect> CalculateNonDraggableRegions(
 - (void)setMouseDownCanMoveWindow:(BOOL)can_move;
 @end
 
+@interface WindowControlView : NSView
+- (void)setupTrackingArea;
+@end
+
+@implementation WindowControlView
+
+- (void)setupTrackingArea {
+  base::scoped_nsobject<NSTrackingArea> trackingArea([[NSTrackingArea alloc]
+      initWithRect:[self bounds]
+      options:(NSTrackingMouseEnteredAndExited | NSTrackingActiveAlways)
+      owner:self
+      userInfo:nil]);
+  [self addTrackingArea:trackingArea];
+}
+
+- (void)mouseEntered:(NSEvent *)theEvent {
+  // Show window control button icons.
+}
+
+- (void)mouseExited:(NSEvent *)theEvent {
+  // Hide window control button icons.
+}
+
+@end
+
 NativeAppWindowCocoa::NativeAppWindowCocoa(
     AppWindow* app_window,
     const AppWindow::CreateParams& params)
@@ -341,12 +375,57 @@ NativeAppWindowCocoa::NativeAppWindowCocoa(
                                  kTitlebarBackgroundViewPaintHeight)]);
     [titlebar_background_view_
         setAutoresizingMask:NSViewWidthSizable | NSViewMinYMargin];
-    [window_view addSubview:titlebar_background_view_
-                 positioned:NSWindowBelow
-                 relativeTo:nil];
     [titlebar_background_view_
              setColor:gfx::SkColorToSRGBNSColor(active_frame_color_)
         inactiveColor:gfx::SkColorToSRGBNSColor(inactive_frame_color_)];
+
+    Class titlebar_class = NSClassFromString(@"NSTitlebarAccessoryViewController");
+    if (titlebar_class) {
+      CGFloat height = 30;
+      base::scoped_nsobject<NSView> container_view(
+          [[NSView alloc] initWithFrame:NSMakeRect(0, NSMaxY([window_view bounds]) - height, NSWidth([window_view bounds]), height)]);
+      [titlebar_background_view_ setFrameOrigin:NSMakePoint(0, 0)];
+      [container_view addSubview: titlebar_background_view_];
+      titlebar_accessory_view_controller_.reset([[titlebar_class alloc] init]);
+      [titlebar_accessory_view_controller_ setView:container_view];
+      [titlebar_accessory_view_controller_ setLayoutAttribute:2];
+
+      CGFloat window_control_view_y = floor(height - 20) / 2;
+      base::scoped_nsobject<WindowControlView> window_control_view(
+          [[WindowControlView alloc] initWithFrame:NSMakeRect(1, window_control_view_y, 60, 20)]);
+      [container_view addSubview:window_control_view];
+      [window_control_view setupTrackingArea];
+
+      CGFloat closeButtonX = 5;
+      CGFloat miniButtonX = 25;
+      CGFloat zoomButtonX = 45;
+
+      NSUInteger styleMask = GetWindowStyleMask();
+      NSButton* closeButton = [NSWindow standardWindowButton:NSWindowCloseButton
+                                                forStyleMask:styleMask];
+      // Vertically center the buttons in the tab strip.
+      CGFloat buttonY = floor((20 - NSHeight([closeButton bounds])) / 2);
+      [closeButton setFrameOrigin:NSMakePoint(closeButtonX, buttonY)];
+      [window_control_view addSubview:closeButton];
+
+      NSButton* miniaturizeButton =
+          [NSWindow standardWindowButton:NSWindowMiniaturizeButton
+                            forStyleMask:styleMask];
+      [miniaturizeButton setFrameOrigin:NSMakePoint(miniButtonX, buttonY)];
+      [window_control_view addSubview:miniaturizeButton];
+
+      NSButton* zoomButton =
+          [NSWindow standardWindowButton:NSWindowZoomButton
+                            forStyleMask:styleMask];
+      [window_control_view addSubview:zoomButton];
+      [zoomButton setFrameOrigin:NSMakePoint(zoomButtonX, buttonY)];
+
+      [window addTitlebarAccessoryViewController:titlebar_accessory_view_controller_];
+    } else {
+      [window_view addSubview:titlebar_background_view_
+                   positioned:NSWindowBelow
+                   relativeTo:nil];
+    }
   }
 
   if (base::mac::IsOSSnowLeopard() &&
@@ -851,11 +930,18 @@ void NativeAppWindowCocoa::WindowDidDeminiaturize() {
 }
 
 void NativeAppWindowCocoa::WindowDidEnterFullscreen() {
+  if (titlebar_accessory_view_controller_)
+    [window() removeTitlebarAccessoryViewControllerAtIndex:0];
   is_fullscreen_ = true;
   app_window_->OSFullscreen();
   app_window_->OnNativeWindowChanged();
 }
 
+void NativeAppWindowCocoa::WindowWillExitFullscreen() {
+  if (titlebar_accessory_view_controller_)
+    [window() addTitlebarAccessoryViewController:titlebar_accessory_view_controller_];
+}
+
 void NativeAppWindowCocoa::WindowDidExitFullscreen() {
   is_fullscreen_ = false;
   if (!shows_fullscreen_controls_)