[MacViews] Frameless app windows: make content view cover title bar.

chrome/browser/ui/views/apps/native_widget_mac_frameless_nswindow.mm

+// Copyright 2015 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/views/apps/native_widget_mac_frameless_nswindow.h"
+
+@implementation NativeWidgetMacFramelessNSWindow
+
++ (NSRect)frameRectForContentRect:(NSRect)contentRect
+                        styleMask:(NSUInteger)mask {
+  return contentRect;
+}
+
++ (NSRect)contentRectForFrameRect:(NSRect)frameRect styleMask:(NSUInteger)mask {
+  return frameRect;
+}
+
+- (NSRect)frameRectForContentRect:(NSRect)contentRect {
+  return contentRect;
+}
+
+- (NSRect)contentRectForFrameRect:(NSRect)frameRect {
+  return frameRect;
+}
+
+@end