Implemented browser side software compositing.

content/browser/renderer_host/software_output_device.h

+// Copyright (c) 2013 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 CONTENT_BROWSER_RENDERER_HOST_SOFTWARE_OUTPUT_DEVICE_H_
+#define CONTENT_BROWSER_RENDERER_HOST_SOFTWARE_OUTPUT_DEVICE_H_
+
+#include "cc/software_output_device.h"
+
+#if defined(OS_WIN)
+#include <windows.h>
+#elif defined(USE_X11)
+#include "ui/base/x/x11_util.h"
+#endif
+
+namespace ui {
+class Compositor;
+}
+
+namespace content {
+
+class SoftwareOutputDevice : public cc::SoftwareOutputDevice {
+ public:
+  SoftwareOutputDevice(ui::Compositor* compositor);

[piman, 2013/03/06 19:22:30]

nit: explicit

[piman, 2013/03/06 19:22:30]

When threaded compositing is on, This class will be called from the thread, from
where you can't call into the ui::Compositor (which is a main thread class
only).

Note: it sounds like you only need the HWND / X Drawable. Maybe you can extract
that at construction time (which happens on the main thread), and keep it
around.

[slavi, 2013/03/06 21:51:20]

Done

[slavi, 2013/03/06 21:51:20]

I think it's fine not to support in-browser threaded composting until all the
pieces fit together.

I've added a CHECK to make sure we're not in threaded mode and created a bug
about the issue at crbug.com/180702

+
+  virtual ~SoftwareOutputDevice();
+
+  virtual void Resize(const gfx::Size& viewport_size) OVERRIDE;
+
+  virtual void EndPaint(cc::SoftwareFrameData* frame_data) OVERRIDE;
+
+ private:
+  ui::Compositor* compositor_;
+
+#if defined(OS_WIN)
+  HDC hdc_;
+  BITMAPINFOHEADER bitmap_header_;
+#elif defined(USE_X11)
+  void ClearImage();
+
+  Display* display_;
+  GC gc_;
+  XImage* image_;
+#endif
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_SOFTWARE_OUTPUT_DEVICE_H_