Send compositor frame IPC with metadata.

cc/compositor_frame_metadata.cc

Index: cc/compositor_frame_metadata.cc
diff --git a/cc/compositor_frame_metadata.cc b/cc/compositor_frame_metadata.cc
new file mode 100644
index 0000000000000000000000000000000000000000..acc81784a25e4831b26ad398923b0d37fe24e8d8
--- /dev/null
+++ b/cc/compositor_frame_metadata.cc
@@ -0,0 +1,18 @@
+// 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 "cc/compositor_frame_metadata.h"
+
+namespace cc {
+
+CompositorFrameMetadata::CompositorFrameMetadata()
+    : page_scale_factor(0),
+      min_page_scale_factor(0),
+      max_page_scale_factor(0) {
+}
+
+CompositorFrameMetadata::~CompositorFrameMetadata() {
+}
+
+}  // namespace cc