Browser side changes for software compositing

content/renderer/gpu/compositor_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_RENDERER_GPU_COMPOSITOR_SOFTWARE_OUTPUT_DEVICE_H_
+#define CONTENT_RENDERER_GPU_COMPOSITOR_SOFTWARE_OUTPUT_DEVICE_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+#include "base/threading/non_thread_safe.h"
+#include "cc/output/software_output_device.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/surface/transport_dib.h"
+
+namespace content {
+
+// This class can be created only on the main thread, but then becomes pinned
+// to a fixed thread when bindToClient is called.
+class CompositorSoftwareOutputDevice
+    : NON_EXPORTED_BASE(public cc::SoftwareOutputDevice),
+      NON_EXPORTED_BASE(public base::NonThreadSafe) {
+public:
+  CompositorSoftwareOutputDevice();
+  virtual ~CompositorSoftwareOutputDevice();
+
+  virtual void Resize(gfx::Size size) OVERRIDE;
+
+  virtual SkCanvas* BeginPaint(gfx::Rect damage_rect) OVERRIDE;
+  virtual void EndPaint(cc::SoftwareFrameData* frame_data) OVERRIDE;
+
+  virtual void ReclaimDIB(TransportDIB::Handle handle) OVERRIDE;
+
+private:
+  size_t ViewportSizeInBytes() const {
+    return 4 * viewport_size_.GetArea();
+  }
+
+  TransportDIB* CreateDIB() {
+    TransportDIB* dib =
+        TransportDIB::Create(ViewportSizeInBytes(), sequence_num_++);
+    CHECK(dib);
+    bool success = dib->Map();
+    CHECK(success);
+    return dib;
+  }
+
+  static const int kNumBuffers = 2;
+  int front_buffer_;
+  int last_buffer_;
+  int num_free_buffers_;
+  ScopedVector<TransportDIB> dibs_;
+  SkBitmap bitmap_;
+  uint32 sequence_num_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_GPU_COMPOSITOR_SOFTWARE_OUTPUT_DEVICE_H_