Make software compositing work on Mac.

content/browser/renderer_host/software_framebuffer.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_FRAMEBUFFER_H
+#define CONTENT_BROWSER_RENDERER_HOST_SOFTWARE_FRAMEBUFFER_H
+
+#include <vector>
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "cc/output/software_frame_data.h"
+#include "cc/resources/single_release_callback.h"
+#include "cc/resources/texture_mailbox.h"
+#include "content/browser/renderer_host/frame_memory_manager.h"
+#include "content/browser/renderer_host/render_widget_host_impl.h"
+
+namespace content {
+
+class MemoryHolder;
+
+class SoftwareFramebufferClient {
+ public:
+  virtual void CurrentSoftwareFrameWasDiscarded() = 0;
+};
+
+class SoftwareFramebuffer

[piman, 2013/10/08 02:58:38]

Naming nitpicking... Just trying to convey the right info in here and in the
callers. This class doesn't represent a single frame buffer, but more of a
helper class that manages the software frame buffers. Maybe
SoftwareFrameManager?

[ccameron, 2013/10/22 07:15:55]

I changed this from MemoryHolder/RWHVAura/FrameMemoryManager to
SoftwareFrame/SoftwareFrameManager/SoftwareFrameMemoryManager.

+    : public base::SupportsWeakPtr<SoftwareFramebuffer>,

[piman, 2013/10/08 02:58:38]

We try to avoid SupportsWeakPtr if we can, replacing with a WeakPtrFactory
member at the end of the class (which is more correct most of the time, because
of destruction order).

[ccameron, 2013/10/22 07:15:55]

Changed this to a WeakPtrFactory hanging off of the SoftwareFrameManagerClient
(== RWHVAura).

+      public FrameContainer {
+ public:
+  SoftwareFramebuffer(SoftwareFramebufferClient* client,
+                      RenderWidgetHostImpl* render_widget_host_impl);
+  virtual ~SoftwareFramebuffer();
+  void WasShown();
+  void WasHidden();
+
+  // Note that it is possible that the new frame will be evicted immediately
+  // after being swapped in, so HasCurrentFrame must be checked before using
+  // the result.
+  void SwapToNewFrame(uint32 output_surface_id,
+                      const cc::SoftwareFrameData* frame_data,
+                      float frame_scale_factor);
+  bool HasCurrentFrame() const { return framebuffer_holder_.get(); }
+  void DiscardCurrentFrame();
+
+  void GetCurrentFrameMailbox(
+      cc::TextureMailbox* mailbox,
+      scoped_ptr<cc::SingleReleaseCallback>* release_callback) const;
+  gfx::Size GetCurrentFrameSizeInPixels() const;
+  gfx::Size GetCurrentFrameSizeInDIP() const;
+  const void* GetCurrentFramePixels() const;
+

[ccameron, 2013/10/03 21:46:00]

This part of the interface seems a bit sloppy. I included these functions as-is
from Aura to separate functional and aesthetic changes (this is largely
aesthetic).

I'd like to look into what can be done to clean this up in a follow-on change.

[ccameron, 2013/10/22 07:15:55]

This is gone now...

+  void SendSoftwareFrameAck(uint32 output_surface_id);
+  void ReleaseSoftwareFrame(
+      uint32 output_surface_id,
+      unsigned software_frame_id);
+  void SendReclaimSoftwareFrames();
+
+  // FrameContainer implementation:
+  virtual void ReleaseCurrentFrame() OVERRIDE;
+
+ private:
+  SoftwareFramebufferClient* client_;
+  RenderWidgetHostImpl* render_widget_host_impl_;
+
+  // This holds the current software framebuffer.
+  scoped_refptr<MemoryHolder> framebuffer_holder_;
+
+  struct ReleasedFrameInfo {
+    ReleasedFrameInfo(uint32 output_id, unsigned software_frame_id)
+        : output_surface_id(output_id), frame_id(software_frame_id) {}
+    uint32 output_surface_id;
+    unsigned frame_id;
+  };
+  std::vector<ReleasedFrameInfo> released_software_frames_;
+
+  DISALLOW_COPY_AND_ASSIGN(SoftwareFramebuffer);
+};
+
+}
+
+#endif