Give the browser window's content view a CALayers

chrome/browser/ui/cocoa/fast_resize_view.mm

 // Copyright (c) 2009 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 <Cocoa/Cocoa.h>
 #import "chrome/browser/ui/cocoa/fast_resize_view.h"
 
+#import <Cocoa/Cocoa.h>
+
 #include "base/logging.h"
+#include "base/command_line.h"
+#include "base/mac/scoped_nsobject.h"
+#include "ui/base/cocoa/animation_utils.h"
+#include "ui/base/ui_base_switches.h"
 
 @interface FastResizeView (PrivateMethods)
 // Lays out this views subviews.  If fast resize mode is on, does not resize any
 // subviews and instead pegs them to the top left.  If fast resize mode is off,
 // sets the subviews' frame to be equal to this view's bounds.
 - (void)layoutSubviews;
 @end
 
 @implementation FastResizeView
 
+- (id)initWithFrame:(NSRect)frameRect {
+  if ((self = [super initWithFrame:frameRect])) {
+    if (!CommandLine::ForCurrentProcess()->HasSwitch(
+            switches::kDisableCoreAnimation)) {
+      ScopedCAActionDisabler disabler;
+      base::scoped_nsobject<CALayer> layer([[CALayer alloc] init]);
+      [layer setBackgroundColor:CGColorGetConstantColor(kCGColorWhite)];
+      [self setLayer:layer];
+      [self setWantsLayer:YES];
+    }
+  }
+  return self;
+}
+
+- (BOOL)isOpaque {
+  return YES;
+}
+
 - (void)setFastResizeMode:(BOOL)fastResizeMode {
   if (fastResizeMode_ == fastResizeMode)
     return;
 
   fastResizeMode_ = fastResizeMode;
 
   // Force a relayout when coming out of fast resize mode.
   if (!fastResizeMode_)
     [self layoutSubviews];
 
@@ skipping 35 matching lines @@
     NSRect frame = [subview frame];
     frame.origin.x = 0;
     frame.origin.y = NSHeight(bounds) - NSHeight(frame);
     [subview setFrame:frame];
   } else {
     [subview setFrame:bounds];
   }
 }
 
 @end