cc: Always create PlaybackImageProvider for raster playback.

The PlaybackImageProvider is required for using the compositor's image
decode cache during raster. Currently we conditionally create it if the
images are known to exist on a tile from discardable image analysis.
This results in an expectation for skia to implement some optimizations
assumed during analysis. Instead always create the provider to ensure
more predictable behaviour.

R=ericrk@chromium.org

Bug: 794690
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
Change-Id: I2e21a88697fd400b43eb54fa6b63e73c591592d5
Reviewed-on: https://chromium-review.googlesource.com/826691Reviewed-by: Eric Karl <ericrk@chromium.org>
Commit-Queue: Khushal <khushalsagar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524264}

cc/tiles/tile_manager.cc

@@ -93,7 +93,7 @@ class RasterTaskImpl : public TileTask {
                  std::unique_ptr<RasterBuffer> raster_buffer,
                  TileTask::Vector* dependencies,
                  bool is_gpu_rasterization,
-                 base::Optional<PlaybackImageProvider> image_provider)
+                 PlaybackImageProvider image_provider)
       : TileTask(!is_gpu_rasterization, dependencies),
         tile_manager_(tile_manager),
         tile_id_(tile->id()),
@@ -113,9 +113,7 @@ class RasterTaskImpl : public TileTask {
         raster_buffer_(std::move(raster_buffer)),
         image_provider_(std::move(image_provider)) {
     DCHECK(origin_thread_checker_.CalledOnValidThread());
-
-    if (image_provider_.has_value())
-      playback_settings_.image_provider = &image_provider_.value();
+    playback_settings_.image_provider = &image_provider_;
   }
 
   // Overridden from Task:
@@ -180,7 +178,7 @@ class RasterTaskImpl : public TileTask {
   int source_frame_number_;
   bool is_gpu_rasterization_;
   std::unique_ptr<RasterBuffer> raster_buffer_;
-  base::Optional<PlaybackImageProvider> image_provider_;
+  PlaybackImageProvider image_provider_;
 
   DISALLOW_COPY_AND_ASSIGN(RasterTaskImpl);
 };
@@ -1216,24 +1214,18 @@ scoped_refptr<TileTask> TileManager::CreateRasterTask(
       raster_buffer_provider_->AcquireBufferForRaster(
           resource, resource_content_id, tile->invalidated_id());
 
-  base::Optional<PlaybackImageProvider> image_provider;
-  const bool has_sync_decoded_images = !sync_decoded_images.empty();
-  const bool has_at_raster_images = !at_raster_images.empty();
-  if (skip_images || has_checker_images || has_sync_decoded_images ||
-      has_at_raster_images) {
-    base::Optional<PlaybackImageProvider::Settings> settings;
-    if (!skip_images) {
-      settings.emplace();
-      settings->images_to_skip = std::move(images_to_skip);
-      settings->at_raster_images = std::move(at_raster_images);
-      settings->image_to_current_frame_index =
-          std::move(image_id_to_current_frame_index);
-    }
-
-    image_provider.emplace(image_controller_.cache(), color_space,
-                           std::move(settings));
+  base::Optional<PlaybackImageProvider::Settings> settings;
+  if (!skip_images) {
+    settings.emplace();
+    settings->images_to_skip = std::move(images_to_skip);
+    settings->at_raster_images = std::move(at_raster_images);
+    settings->image_to_current_frame_index =
+        std::move(image_id_to_current_frame_index);
   }
 
+  PlaybackImageProvider image_provider(image_controller_.cache(), color_space,
+                                       std::move(settings));
+
   return base::MakeRefCounted<RasterTaskImpl>(
       this, tile, resource, prioritized_tile.raster_source(), playback_settings,
       prioritized_tile.priority().resolution, invalidated_rect,