Add the ability for the GPU process to be used to paint the backing store of a
tab. This is the first pass and is currently a bit buggy and incomplete.

This patch refactors the backing store to make it a virtual interface which is
then implemented by the platform-specific backing stores. This cleans up the
multi-platform aspects of the old code, and also makes it possible to create
different backing stores (such as ones in another process).

This renames the BackingStore::PaintRect function to PaintToBackingStore which
clears up what it does. I would often get confused and think that it paints
the backing store to the screen.

This makes a common way to capture backing store information and adds it to the
backing store API. This removed a bunch of ugly ifdefs.

This adds the ability for a backing store to specify that the TransportDIB
should not be freed by RenderWidgetHost when painting is complete. This is
necessary since the out-of-process version needs to use it after the
RenderWidget paint function has returned.

This pushes up the vector of copy_rect from RenderWidgetHost to the actual
BackingStores. This prevents us from sending duplicate data over IPC. It also
makes the common non-IPC case more efficient, since we end up setting up various
surfaces only once when there are multiple update rects.

BUG=none
TEST=none
Review URL: http://codereview.chromium.org/523028

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@36075 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/gpu/gpu_process.h b/chrome/gpu/gpu_process.h
new file mode 100644
index 0000000..92c73a67
--- /dev/null
+++ b/chrome/gpu/gpu_process.h
@@ -0,0 +1,19 @@
+// Copyright (c) 2010 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 CHROME_GPU_GPU_PROCESS_H_
+#define CHROME_GPU_GPU_PROCESS_H_
+
+#include "chrome/common/child_process.h"
+
+class GpuProcess : public ChildProcess {
+ public:
+  GpuProcess();
+  ~GpuProcess();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(GpuProcess);
+};
+
+#endif  // CHROME_GPU_GPU_PROCESS_H_