cc: Add image decode queue functionality to image manager.

cc/tiles/gpu_image_decode_cache.h

 // Copyright 2016 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_TILES_GPU_IMAGE_DECODE_CACHE_H_
 #define CC_TILES_GPU_IMAGE_DECODE_CACHE_H_
 
 #include <memory>
 #include <unordered_map>
 #include <vector>
@@ skipping 81 matching lines @@
 //      same ImageDatas (and may need to keep these ImageDatas alive independent
 //      of each other), they hold ImageDatas by scoped_refptr. The scoped_refptr
 //      keeps an ImageData alive while it is present in either the
 //      |persistent_cache_| or |in_use_cache_|.
 //
 class CC_EXPORT GpuImageDecodeCache
     : public ImageDecodeCache,
       public base::trace_event::MemoryDumpProvider,
       public base::MemoryCoordinatorClient {
  public:
+  enum class DecodeTaskType { PART_OF_UPLOAD_TASK, STAND_ALONE_DECODE_TASK };
+
   explicit GpuImageDecodeCache(ContextProvider* context,
                                ResourceFormat decode_format,
                                size_t max_gpu_image_bytes);
   ~GpuImageDecodeCache() override;
 
   // ImageDecodeCache overrides.
 
   // Finds the existing uploaded image for the provided DrawImage. Creates an
   // upload task to upload the image if an exsiting image does not exist.
   bool GetTaskForImageAndRef(const DrawImage& image,
                              const TracingInfo& tracing_info,
                              scoped_refptr<TileTask>* task) override;
+  bool GetOutOfRasterDecodeTaskForImageAndRef(
+      const DrawImage& image,
+      scoped_refptr<TileTask>* task) override;
   void UnrefImage(const DrawImage& image) override;
   DecodedDrawImage GetDecodedImageForDraw(const DrawImage& draw_image) override;
   void DrawWithImageFinished(const DrawImage& image,
                              const DecodedDrawImage& decoded_image) override;
   void ReduceCacheUsage() override;
   void SetShouldAggressivelyFreeResources(
       bool aggressively_free_resources) override;
 
   // MemoryDumpProvider overrides.
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                     base::trace_event::ProcessMemoryDump* pmd) override;
 
   // base::MemoryCoordinatorClient overrides.
   void OnMemoryStateChange(base::MemoryState state) override;
 
   // Called by Decode / Upload tasks.
   void DecodeImage(const DrawImage& image);
   void UploadImage(const DrawImage& image);
 
   // Called by Decode / Upload tasks when tasks are finished.
-  void OnImageDecodeTaskCompleted(const DrawImage& image);
+  void OnImageDecodeTaskCompleted(const DrawImage& image,
+                                  DecodeTaskType task_type);
   void OnImageUploadTaskCompleted(const DrawImage& image);
 
   // For testing only.
   void SetCachedBytesLimitForTesting(size_t limit) {
     cached_bytes_limit_ = limit;
   }
   size_t GetBytesUsedForTesting() const { return bytes_used_; }
   size_t GetNumCacheEntriesForTesting() const {
     return persistent_cache_.size();
   }
@@ skipping 15 matching lines @@
     void SetLockedData(std::unique_ptr<base::DiscardableMemory> data);
     void ResetData();
     base::DiscardableMemory* data() const { return data_.get(); }
     void mark_used() { usage_stats_.used = true; }
 
     uint32_t ref_count = 0;
     // Set to true if the image was corrupt and could not be decoded.
     bool decode_failure = false;
     // If non-null, this is the pending decode task for this image.
     scoped_refptr<TileTask> task;
+    // Similar to above, but only is generated if there is no associated upload
+    // generated for this task (ie, this is an out-of-raster request for decode.
+    scoped_refptr<TileTask> stand_alone_task;
 
    private:
     struct UsageStats {
       int lock_count = 1;
       bool used = false;
       bool first_lock_wasted = false;
     };
 
     void ReportUsageStats() const;
 
@@ skipping 75 matching lines @@
   using InUseCacheKey = uint64_t;
 
   // All private functions should only be called while holding |lock_|. Some
   // functions also require the |context_| lock. These are indicated by
   // additional comments.
 
   // Similar to GetTaskForImageAndRef, but gets the dependent decode task
   // rather than the upload task, if necessary.
   scoped_refptr<TileTask> GetImageDecodeTaskAndRef(
       const DrawImage& image,
-      const TracingInfo& tracing_info);
+      const TracingInfo& tracing_info,
+      DecodeTaskType task_type);
+
+  // Note that this function behaves as if it was public (all of the same locks
+  // need to be acquired).
+  bool GetTaskForImageAndRefInternal(const DrawImage& image,
+                                     const TracingInfo& tracing_info,
+                                     DecodeTaskType task_type,
+                                     scoped_refptr<TileTask>* task);
 
   void RefImageDecode(const DrawImage& draw_image);
   void UnrefImageDecode(const DrawImage& draw_image);
   void RefImage(const DrawImage& draw_image);
   void UnrefImageInternal(const DrawImage& draw_image);
 
   // Called any time the ownership of an object changed. This includes changes
   // to ref-count or to orphaned status.
   void OwnershipChanged(const DrawImage& draw_image, ImageData* image_data);
 
@@ skipping 49 matching lines @@
 
   // We can't release GPU backed SkImages without holding the context lock,
   // so we add them to this list and defer deletion until the next time the lock
   // is held.
   std::vector<sk_sp<SkImage>> images_pending_deletion_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TILES_GPU_IMAGE_DECODE_CACHE_H_