Simplify rate limiting since it's main thread shared context only

cc/scheduler/rate_limiter.cc

Index: cc/scheduler/rate_limiter.cc
diff --git a/cc/scheduler/rate_limiter.cc b/cc/scheduler/rate_limiter.cc
deleted file mode 100644
index d89d95b8cf23acfbb5ae886fbf3b972de9d9c51e..0000000000000000000000000000000000000000
--- a/cc/scheduler/rate_limiter.cc
+++ /dev/null
@@ -1,61 +0,0 @@
-// Copyright 2011 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 "cc/scheduler/rate_limiter.h"
-
-#include "base/bind.h"
-#include "base/debug/trace_event.h"
-#include "base/location.h"
-#include "base/logging.h"
-#include "base/single_thread_task_runner.h"
-#include "third_party/WebKit/public/platform/WebGraphicsContext3D.h"
-
-namespace cc {
-
-scoped_refptr<RateLimiter> RateLimiter::Create(
-    WebKit::WebGraphicsContext3D* context,
-    RateLimiterClient* client,
-    base::SingleThreadTaskRunner* task_runner) {
-  return make_scoped_refptr(new RateLimiter(context, client, task_runner));
-}
-
-RateLimiter::RateLimiter(WebKit::WebGraphicsContext3D* context,
-                         RateLimiterClient* client,
-                         base::SingleThreadTaskRunner* task_runner)
-    : context_(context),
-      active_(false),
-      client_(client),
-      task_runner_(task_runner) {
-  DCHECK(context);
-}
-
-RateLimiter::~RateLimiter() {}
-
-void RateLimiter::Start() {
-  if (active_)
-    return;
-
-  TRACE_EVENT0("cc", "RateLimiter::Start");
-  active_ = true;
-  task_runner_->PostTask(FROM_HERE,
-                         base::Bind(&RateLimiter::RateLimitContext, this));
-}
-
-void RateLimiter::Stop() {
-  TRACE_EVENT0("cc", "RateLimiter::Stop");
-  client_ = NULL;
-}
-
-void RateLimiter::RateLimitContext() {
-  if (!client_)
-    return;
-
-  TRACE_EVENT0("cc", "RateLimiter::RateLimitContext");
-
-  active_ = false;
-  client_->RateLimit();
-  context_->rateLimitOffscreenContextCHROMIUM();
-}
-
-}  // namespace cc