Introduce CompositorDependencies for RenderWidgetCompositor.

cc/test/fake_external_begin_frame_source.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 "cc/test/fake_external_begin_frame_source.h"
+
+#include "base/location.h"
+#include "base/message_loop/message_loop.h"
+#include "base/time/time.h"
+#include "cc/test/begin_frame_args_test.h"
+
+namespace cc {
+
+FakeExternalBeginFrameSource::FakeExternalBeginFrameSource(double refresh_rate)
+    : milliseconds_per_frame_(1000.0 / refresh_rate),
+      is_ready_(false),
+      weak_ptr_factory_(this) {
+  DetachFromThread();
+}
+
+FakeExternalBeginFrameSource::~FakeExternalBeginFrameSource() {
+  DCHECK(CalledOnValidThread());
+}
+
+void FakeExternalBeginFrameSource::SetClientReady() {
+  DCHECK(CalledOnValidThread());
+  is_ready_ = true;
+}
+
+void FakeExternalBeginFrameSource::OnNeedsBeginFramesChange(
+    bool needs_begin_frames) {
+  DCHECK(CalledOnValidThread());
+  if (needs_begin_frames) {
+    base::MessageLoop::current()->PostDelayedTask(
+        FROM_HERE, base::Bind(&FakeExternalBeginFrameSource::TestOnBeginFrame,
+                              weak_ptr_factory_.GetWeakPtr()),
+        base::TimeDelta::FromMilliseconds(milliseconds_per_frame_));
+  }
+}
+
+void FakeExternalBeginFrameSource::TestOnBeginFrame() {
+  DCHECK(CalledOnValidThread());
+  CallOnBeginFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
+}
+
+}  // namespace cc