Add hints for potential overlay promotion on android.

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 <stddef.h>
 #include <stdint.h>
 
@@ skipping 46 matching lines @@
 
 // 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
     : public base::trace_event::MemoryDumpProvider {
  private:
   struct Resource;
 
  public:
   using ResourceIdArray = std::vector<ResourceId>;
-  using ResourceIdSet = std::unordered_set<ResourceId>;
   using ResourceIdMap = std::unordered_map<ResourceId, ResourceId>;
   enum TextureHint {
     TEXTURE_HINT_DEFAULT = 0x0,
     TEXTURE_HINT_IMMUTABLE = 0x1,
     TEXTURE_HINT_FRAMEBUFFER = 0x2,
     TEXTURE_HINT_IMMUTABLE_FRAMEBUFFER =
         TEXTURE_HINT_IMMUTABLE | TEXTURE_HINT_FRAMEBUFFER
   };
   enum ResourceType {
     RESOURCE_TYPE_GPU_MEMORY_BUFFER,
@@ skipping 122 matching lines @@
   void DeclareUsedResourcesFromChild(int child,
                                      const ResourceIdSet& resources_from_child);
 
   // Receives resources from the parent, moving them from mailboxes. Resource
   // IDs passed are in the child namespace.
   // NOTE: if the sync_token is set on any TransferableResource, this will
   // wait on it.
   void ReceiveReturnsFromParent(
       const ReturnedResourceArray& transferable_resources);
 
+#if defined(OS_ANDROID)
+  // Send an overlay promotion hint to all resources that requested it via
+  // |want_promotion_hint|.  |promotable_hints| contains all the resources that
+  // should be told that they're promotable.  Others will be told that they're
+  // not promotable right now.
+  void SendPromotionHints(const ResourceIdSet& promotable_hints);
+#endif
+
   // The following lock classes are part of the ResourceProvider API and are
   // needed to read and write the resource contents. The user must ensure
   // that they only use GL locks on GL resources, etc, and this is enforced
   // by assertions.
   class CC_EXPORT ScopedReadLockGL {
    public:
     ScopedReadLockGL(ResourceProvider* resource_provider,
                      ResourceId resource_id);
     ~ScopedReadLockGL();
 
@@ skipping 244 matching lines @@
   // and has read fences enabled, the resource will not allow writes
   // until this fence has passed.
   void SetReadLockFence(Fence* fence) { current_read_lock_fence_ = fence; }
 
   // Indicates if we can currently lock this resource for write.
   bool CanLockForWrite(ResourceId id);
 
   // Indicates if this resource may be used for a hardware overlay plane.
   bool IsOverlayCandidate(ResourceId id);
 
+#if defined(OS_ANDROID)
+  // Indicates if this resource is backed by an Android SurfaceTexture, and thus
+  // can't really be promoted to an overlay.
+  bool IsBackedBySurfaceTexture(ResourceId id);
+
+  // Indicates if this resource wants to receive promotion hints.
+  bool WantsPromotionHint(ResourceId id);
+
+  // Return the number of resources that request promotion hints.
+  size_t CountPromotionHintRequestsForTesting();
+#endif
+
   void WaitSyncTokenIfNeeded(ResourceId id);
 
   static GLint GetActiveTextureUnit(gpu::gles2::GLES2Interface* gl);
 
   void ValidateResource(ResourceId id) const;
 
   GLenum GetImageTextureTarget(gfx::BufferUsage usage, ResourceFormat format);
 
   // base::trace_event::MemoryDumpProvider implementation.
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
@@ skipping 83 matching lines @@
     int imported_count;
     int exported_count;
     bool dirty_image : 1;
     bool locked_for_write : 1;
     bool lost : 1;
     bool marked_for_deletion : 1;
     bool allocated : 1;
     bool read_lock_fences_enabled : 1;
     bool has_shared_bitmap_id : 1;
     bool is_overlay_candidate : 1;
+#if defined(OS_ANDROID)
+    // Indicates whether this resource may not be overlayed on Android, since
+    // it's not backed by a SurfaceView.  This may be set in combination with
+    // |is_overlay_candidate|, to find out if switching the resource to a
+    // a SurfaceView would result in overlay promotion.  It's good to find this
+    // out in advance, since one has no fallback path for displaying a
+    // SurfaceView except via promoting it to an overlay.  Ideally, one _could_
+    // promote SurfaceTexture via the overlay path, even if one ended up just
+    // drawing a quad in the compositor.  However, for now, we use this flag to
+    // refuse to promote so that the compositor will draw the quad.
+    bool is_backed_by_surface_texture : 1;
+    // Indicates that this resource would like a promotion hint.
+    bool wants_promotion_hint : 1;
+#endif
     scoped_refptr<Fence> read_lock_fence;
     gfx::Size size;
     Origin origin;
     GLenum target;
     // TODO(skyostil): Use a separate sampler object for filter state.
     GLenum original_filter;
     GLenum filter;
     unsigned image_id;
     unsigned bound_image_id;
     TextureHint hint;
@@ skipping 117 matching lines @@
   const size_t id_allocation_chunk_size_;
   std::unique_ptr<IdAllocator> texture_id_allocator_;
   std::unique_ptr<IdAllocator> buffer_id_allocator_;
 
   bool use_sync_query_;
   BufferToTextureTargetMap buffer_to_texture_target_map_;
 
   // A process-unique ID used for disambiguating memory dumps from different
   // resource providers.
   int tracing_id_;
+#if defined(OS_ANDROID)
+  // Set of resource Ids that would like to be notified about promotion hints.
+  ResourceIdSet wants_promotion_hints_set_;
+#endif
 
   DISALLOW_COPY_AND_ASSIGN(ResourceProvider);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_PROVIDER_H_