Re-enable native UI for {frame:'chrome'} in app windows.

chrome/browser/ui/cocoa/extensions/shell_window_cocoa.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.
 
 #include "chrome/browser/ui/cocoa/extensions/shell_window_cocoa.h"
 
 #include "base/mac/mac_util.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/cocoa/browser_window_utils.h"
@@ skipping 68 matching lines @@
 }
 
 - (BOOL)handledByExtensionCommand:(NSEvent*)event {
   if (shellWindow_)
     return shellWindow_->HandledByExtensionCommand(event);
   return NO;
 }
 
 @end
 
-@interface ShellNSWindow : ChromeEventProcessingWindow
-
-- (void)drawCustomFrameRect:(NSRect)rect forView:(NSView*)view;
-
-@end
-
 // This is really a method on NSGrayFrame, so it should only be called on the
 // view passed into -[NSWindow drawCustomFrameRect:forView:].
 @interface NSView (PrivateMethods)
 - (CGFloat)roundedCornerRadius;
 @end
 
+@interface ShellNSWindow : ChromeEventProcessingWindow
+
+- (void)drawCustomFrameRect:(NSRect)rect forView:(NSView*)view;
+
+@end
+
 @implementation ShellNSWindow
 
 - (void)drawCustomFrameRect:(NSRect)rect forView:(NSView*)view {
   [[NSBezierPath bezierPathWithRect:rect] addClip];
   [[NSColor clearColor] set];
   NSRectFill(rect);
 
   // Set up our clip.
   CGFloat cornerRadius = 4.0;
   if ([view respondsToSelector:@selector(roundedCornerRadius)])
     cornerRadius = [view roundedCornerRadius];
   [[NSBezierPath bezierPathWithRoundedRect:[view bounds]
                                    xRadius:cornerRadius
                                    yRadius:cornerRadius] addClip];
   [[NSColor whiteColor] set];
   NSRectFill(rect);
 }
 
+@end
+
+@interface ShellFramelessNSWindow : ShellNSWindow
+
+@end
+
+@implementation ShellFramelessNSWindow
+
 + (NSRect)frameRectForContentRect:(NSRect)contentRect
                         styleMask:(NSUInteger)mask {
   return contentRect;
 }
 
 + (NSRect)contentRectForFrameRect:(NSRect)frameRect
                         styleMask:(NSUInteger)mask {
   return frameRect;
 }
 
@@ skipping 39 matching lines @@
         (NSWidth(main_screen_rect) - NSWidth(cocoa_bounds)) / 2;
   }
   if (params.bounds.y() < 0) {
     cocoa_bounds.origin.y =
         (NSHeight(main_screen_rect) - NSHeight(cocoa_bounds)) / 2;
   }
 
   NSUInteger style_mask = NSTitledWindowMask | NSClosableWindowMask |
                           NSMiniaturizableWindowMask | NSResizableWindowMask |
                           NSTexturedBackgroundWindowMask;
-  scoped_nsobject<NSWindow> window([[ShellNSWindow alloc]
-      initWithContentRect:cocoa_bounds
-                styleMask:style_mask
-                  backing:NSBackingStoreBuffered
-                    defer:NO]);
+  scoped_nsobject<NSWindow> window;
+  if (has_frame_) {
+    window.reset([[ShellNSWindow alloc]
+        initWithContentRect:cocoa_bounds
+                  styleMask:style_mask
+                    backing:NSBackingStoreBuffered
+                      defer:NO]);
+  } else {
+    window.reset([[ShellFramelessNSWindow alloc]
+        initWithContentRect:cocoa_bounds
+                  styleMask:style_mask
+                    backing:NSBackingStoreBuffered
+                      defer:NO]);
+  }
   [window setTitle:base::SysUTF8ToNSString(extension()->name())];
   gfx::Size min_size = params.minimum_size;
   if (min_size.width() || min_size.height()) {
     [window setContentMinSize:NSMakeSize(min_size.width(), min_size.height())];
   }
   gfx::Size max_size = params.maximum_size;
   if (max_size.width() || max_size.height()) {
     CGFloat max_width = max_size.width() ? max_size.width() : CGFLOAT_MAX;
     CGFloat max_height = max_size.height() ? max_size.height() : CGFLOAT_MAX;
     [window setContentMaxSize:NSMakeSize(max_width, max_height)];
@@ skipping 325 matching lines @@
   NSWindow* window = [window_controller_ window];
   CHECK(!window || [window isKindOfClass:[ShellNSWindow class]]);
   return static_cast<ShellNSWindow*>(window);
 }
 
 // static
 NativeShellWindow* NativeShellWindow::Create(
     ShellWindow* shell_window, const ShellWindow::CreateParams& params) {
   return new ShellWindowCocoa(shell_window, params);
 }