Cleanup unused #includes and declarations in PlatformImpl

sky/engine/testing/platform/platform_impl.cc

 // Copyright 2014 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 "sky/engine/testing/platform/platform_impl.h"
 
-#include <cmath>
-
-#include "base/rand_util.h"
-#include "base/stl_util.h"
-#include "base/synchronization/waitable_event.h"
-#include "base/time/time.h"
-#include "net/base/data_url.h"
-#include "net/base/mime_util.h"
-#include "net/base/net_errors.h"
-
 namespace sky {
 
 PlatformImpl::PlatformImpl() {
 }
 
 PlatformImpl::~PlatformImpl() {
 }
 
 blink::WebString PlatformImpl::defaultLocale() {
   return blink::WebString::fromUTF8("en-US");
 }
 
 blink::WebUnitTestSupport* PlatformImpl::unitTestSupport() {
   return &unit_test_support_;
 }
 
 }  // namespace sky