Use proper namespace in skia/ext

chrome/browser/ui/cocoa/constrained_window/constrained_window_custom_window.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.
 
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_custom_window.h"
 
 #import "base/mac/scoped_nsobject.h"
 #import "chrome/browser/ui/chrome_style.h"
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_sheet_controller.h"
 #include "skia/ext/skia_utils_mac.h"
@@ skipping 22 matching lines @@
 
 - (id)initWithContentRect:(NSRect)contentRect
                 styleMask:(NSUInteger)windowStyle
                   backing:(NSBackingStoreType)bufferingType
                     defer:(BOOL)deferCreation {
   if ((self = [super initWithContentRect:contentRect
                                styleMask:windowStyle
                                  backing:bufferingType
                                    defer:NO])) {
     [self setHasShadow:YES];
-    [self setBackgroundColor:gfx::SkColorToCalibratedNSColor(
+    [self setBackgroundColor:skia::SkColorToCalibratedNSColor(
         chrome_style::GetBackgroundColor())];
     [self setOpaque:NO];
     [self setReleasedWhenClosed:NO];
   }
   return self;
 }
 
 - (BOOL)canBecomeKeyWindow {
   return YES;
 }
@@ skipping 32 matching lines @@
   [path setWindingRule:NSEvenOddWindingRule];
   [[NSGraphicsContext currentContext] setCompositingOperation:
       NSCompositeCopy];
   [[NSColor clearColor] set];
   [path fill];
 
   [[self window] invalidateShadow];
 }
 
 @end