Split ThreadProxy methods to ProxyMain and ProxyImpl.

cc/trees/proxy_common.h

Index: cc/trees/proxy_common.h
diff --git a/cc/trees/proxy_common.h b/cc/trees/proxy_common.h
new file mode 100644
index 0000000000000000000000000000000000000000..5fce5e48a643f39e962d62f304205dc6513abb42
--- /dev/null
+++ b/cc/trees/proxy_common.h
@@ -0,0 +1,28 @@
+// Copyright 2015 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.
+
+#ifndef CC_TREES_PROXY_COMMON_H_
+#define CC_TREES_PROXY_COMMON_H_
+
+#include "cc/base/cc_export.h"
+#include "cc/output/begin_frame_args.h"
+#include "cc/trees/layer_tree_host_common.h"
+
+namespace cc {
+class LayerTreeHost;
+
+struct CC_EXPORT BeginMainFrameAndCommitState {
+  BeginMainFrameAndCommitState();
+  ~BeginMainFrameAndCommitState();
+
+  unsigned int begin_frame_id;
+  BeginFrameArgs begin_frame_args;
+  scoped_ptr<ScrollAndScaleSet> scroll_info;
+  size_t memory_allocation_limit_bytes;
+  bool evicted_ui_resources;
+};
+
+}  // namespace cc
+
+#endif  // CC_TREES_PROXY_COMMON_H_