[Aura] Added Support for rendering software compositor frames as cc::TextureLayers.

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/memory/shared_memory.h"
 #include "base/threading/non_thread_safe.h"
 #include "cc/output/software_output_device.h"
+#include "content/public/renderer/render_thread.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
+class SkRegion;
+
 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(const TransportDIB::Id& id) OVERRIDE;
+  virtual void ReclaimSoftwareFrame(unsigned id) OVERRIDE;
 
 private:
-  class DIB {
+  // Internal buffer class that manages shared memory lifetime and ownership.
+  // It also tracks buffers' history so we can calculate what's the minimum
+  // damage rect difference between any two given buffers (see SetParent and
+  // FindDamageDifferenceFrom).
+  class Buffer {
    public:
-    explicit DIB(size_t size);
-    ~DIB();
+    explicit Buffer(unsigned id, scoped_ptr<base::SharedMemory> mem);
+    ~Buffer();
 
-    TransportDIB* dib() const {
-      return dib_;
-    }
+    unsigned id() const { return id_; }
+
+    void* memory() const { return mem_->memory(); }
+    base::SharedMemoryHandle handle() const { return mem_->handle(); }
+
+    bool free() const { return free_; }
+    void SetFree(bool free) { free_ = free; }
+
+    Buffer* parent() const { return parent_; }
+    void SetParent(Buffer* parent, const gfx::Rect& damage);
+
+    bool FindDamageDifferenceFrom(Buffer* buffer, SkRegion* result) const;
 
    private:
-    TransportDIB* dib_;
+    const unsigned id_;
+    scoped_ptr<base::SharedMemory> mem_;
+    bool free_;
+    Buffer* parent_;
+    gfx::Rect damage_;
 
-    DISALLOW_COPY_AND_ASSIGN(DIB);
+    DISALLOW_COPY_AND_ASSIGN(Buffer);
   };
 
   class CompareById {
    public:
-    CompareById(const TransportDIB::Id& id) : id_(id) {}
+    CompareById(unsigned id) : id_(id) {}
 
-    bool operator()(const DIB* dib) const {
-      return dib->dib() && dib->dib()->id() == id_;
+    bool operator()(const Buffer* buffer) const {
+      return buffer->id() == id_;
     }
 
    private:
-    TransportDIB::Id id_;
+    const unsigned id_;
   };
 
-  DIB* CreateDIB();
+  unsigned GetNextId();
+  Buffer* CreateBuffer();
+  size_t FindFreeBuffer(size_t hint);
 
-  int front_buffer_;
-  int num_free_buffers_;
-  ScopedVector<DIB> dibs_;
-  ScopedVector<DIB> awaiting_ack_;
+  size_t current_index_;
+  unsigned next_buffer_id_;
+  ScopedVector<Buffer> buffers_;
+  ScopedVector<Buffer> awaiting_ack_;
   SkBitmap bitmap_;
+  RenderThread* render_thread_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_GPU_COMPOSITOR_SOFTWARE_OUTPUT_DEVICE_H_