cc: Refactor SkipImageCanvas and create it during playback.

cc/playback/display_list_raster_source.cc

 // Copyright 2014 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.
 
 #include "cc/playback/display_list_raster_source.h"
 
 #include <stddef.h>
 
 #include "base/strings/stringprintf.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/base/region.h"
 #include "cc/debug/debug_colors.h"
 #include "cc/playback/display_item_list.h"
 #include "cc/playback/image_hijack_canvas.h"
+#include "cc/playback/skip_image_canvas.h"
 #include "skia/ext/analysis_canvas.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
 #include "third_party/skia/include/core/SkTLazy.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 
 namespace cc {
 
 scoped_refptr<DisplayListRasterSource>
 DisplayListRasterSource::CreateFromDisplayListRecordingSource(
@@ skipping 62 matching lines @@
   // For MemoryDumpProvider deregistration to work correctly, this must happen
   // on the same thread that the DisplayListRasterSource was created on.
   DCHECK(memory_dump_thread_checker_.CalledOnValidThread());
   base::trace_event::MemoryDumpManager::GetInstance()->UnregisterDumpProvider(
       this);
 }
 
 void DisplayListRasterSource::PlaybackToSharedCanvas(
     SkCanvas* raster_canvas,
     const gfx::Rect& canvas_rect,
-    float contents_scale) const {
+    float contents_scale,
+    bool include_images) const {
   // TODO(vmpstr): This can be improved by plumbing whether the tile itself has
   // discardable images. This way we would only pay for the hijack canvas if the

[ericrk, 2016/03/14 21:40:13]

nit: comment probably applies to both cases - not just discardable - if a tile
has no images, we don't want to pay the cost of the SkipImagesCanvas?

   // tile actually needed it.
-  if (display_list_->MayHaveDiscardableImages()) {
+  if (!include_images) {
+    SkipImageCanvas canvas(raster_canvas);
+    RasterCommon(&canvas, nullptr, canvas_rect, canvas_rect, contents_scale);
+  } else if (display_list_->MayHaveDiscardableImages()) {
     const SkImageInfo& info = raster_canvas->imageInfo();
     ImageHijackCanvas canvas(info.width(), info.height(),
                              image_decode_controller_);
     canvas.addCanvas(raster_canvas);
 
     RasterCommon(&canvas, nullptr, canvas_rect, canvas_rect, contents_scale);
   } else {
     RasterCommon(raster_canvas, nullptr, canvas_rect, canvas_rect,
                  contents_scale);
   }
 }
 
 void DisplayListRasterSource::RasterForAnalysis(skia::AnalysisCanvas* canvas,
                                                 const gfx::Rect& canvas_rect,
                                                 float contents_scale) const {
   RasterCommon(canvas, canvas, canvas_rect, canvas_rect, contents_scale);
 }
 
 void DisplayListRasterSource::PlaybackToCanvas(
     SkCanvas* raster_canvas,
     const gfx::Rect& canvas_bitmap_rect,
     const gfx::Rect& canvas_playback_rect,
-    float contents_scale) const {
+    float contents_scale,
+    bool include_images) const {
   PrepareForPlaybackToCanvas(raster_canvas, canvas_bitmap_rect,
                              canvas_playback_rect, contents_scale);
 
-  if (display_list_->MayHaveDiscardableImages()) {
+  if (!include_images) {
+    SkipImageCanvas canvas(raster_canvas);
+    RasterCommon(&canvas, nullptr, canvas_bitmap_rect, canvas_playback_rect,
+                 contents_scale);
+  } else if (display_list_->MayHaveDiscardableImages()) {
     const SkImageInfo& info = raster_canvas->imageInfo();
     ImageHijackCanvas canvas(info.width(), info.height(),
                              image_decode_controller_);
     canvas.addCanvas(raster_canvas);
     RasterCommon(&canvas, nullptr, canvas_bitmap_rect, canvas_playback_rect,
                  contents_scale);
   } else {
     RasterCommon(raster_canvas, nullptr, canvas_bitmap_rect,
                  canvas_playback_rect, contents_scale);
   }
@@ skipping 234 matching lines @@
     base::trace_event::MemoryAllocatorDump* dump =
         pmd->CreateAllocatorDump(dump_name);
     dump->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
                     base::trace_event::MemoryAllocatorDump::kUnitsBytes,
                     memory_usage);
   }
   return true;
 }
 
 }  // namespace cc