Use a direct include of strings headers in extensions/, google_apis/, gpu/.

gpu/command_buffer/service/gpu_tracer.cc

 // 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 "gpu/command_buffer/service/gpu_tracer.h"
 
 #include <deque>
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/memory/weak_ptr.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "base/threading/thread.h"
 #include "base/time.h"
 #include "ui/gl/gl_bindings.h"
 
 namespace gpu {
 namespace gles2 {
 namespace {
 
 class Outputter;
 
@@ skipping 315 matching lines @@
 }  // namespace
 
 scoped_ptr<GPUTracer> GPUTracer::Create() {
   if (gfx::g_driver_gl.ext.b_GL_ARB_timer_query)
     return scoped_ptr<GPUTracer>(new GPUTracerARBTimerQuery());
   return scoped_ptr<GPUTracer>(new GPUTracerImpl());
 }
 
 }  // namespace gles2
 }  // namespace gpu