cc: Move video upload to VideoResourceUpdater.

cc/resources/resource_provider.h

 // Copyright 2012 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 CC_RESOURCES_RESOURCE_PROVIDER_H_
 #define CC_RESOURCES_RESOURCE_PROVIDER_H_
 
 #include <deque>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface.h"
 #include "cc/output/texture_copier.h"
 #include "cc/resources/texture_mailbox.h"
 #include "cc/resources/transferable_resource.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/gfx/size.h"
 
 namespace WebKit {
 class WebGraphicsContext3D;
 }
 
 namespace gfx {
 class Rect;
 class Vector2d;
 }
 
 namespace cc {
 class TextureUploader;
 
 // This class is not thread-safe and can only be called from the thread it was
-// created on (in practice, the impl thread).
-class CC_EXPORT ResourceProvider {
+// created on (in practice, the impl thread). It supports WeakPtr in order to
+// tell when the provider and the context it holds is destroyed and no longer
+// usable.
+class CC_EXPORT ResourceProvider
+    : public base::SupportsWeakPtr<ResourceProvider> {

[piman, 2013/04/08 21:03:47]

Will the VideoResourceUpdater outlive the layer? It doesn't now but I'm not
entirely sure where this is going.
If it doesn't outlive the layer, then we can avoid this by relying on the
DidLoseOutputSurface callback in the layer.

I'm somewhat worried that serving a weak pointer here gives an easy way out, but
may prove problematic for cases where the RP gets destroyed without a context
loss (e.g. compositor teardown), but before the resources are properly released
- and it's then too late and we leak them.

[danakj, 2013/04/08 21:44:56]

Removed this as per offline convo. The callback is called from RP, so it doesn't
need to worry about getting called after the RP is destroyed.

  public:
   typedef unsigned ResourceId;
   typedef std::vector<ResourceId> ResourceIdArray;
   typedef std::set<ResourceId> ResourceIdSet;
   typedef base::hash_map<ResourceId, ResourceId> ResourceIdMap;
   enum TextureUsageHint {
     TextureUsageAny,
     TextureUsageFramebuffer,
   };
   enum ResourceType {
@@ skipping 338 matching lines @@
   base::ThreadChecker thread_checker_;
 
   scoped_refptr<Fence> current_read_lock_fence_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceProvider);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_PROVIDER_H_