cc: Do solid color analysis before scheduling tiles.

cc/tiles/tile_manager.cc

 // 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.
 
 #include "cc/tiles/tile_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 37 matching lines @@
                  const gfx::Rect& invalid_content_rect,
                  float contents_scale,
                  TileResolution tile_resolution,
                  int layer_id,
                  uint64_t source_prepare_tiles_id,
                  const void* tile,
                  uint64_t new_content_id,
                  uint64_t previous_content_id,
                  uint64_t resource_content_id,
                  int source_frame_number,
-                 bool analyze_picture,
-                 const base::Callback<
-                     void(const DisplayListRasterSource::SolidColorAnalysis&,
-                          bool)>& reply,
+                 const base::Callback<void(bool)>& reply,
                  ImageDecodeTask::Vector* dependencies)
       : RasterTask(dependencies),
         resource_(resource),
         raster_source_(raster_source),
         content_rect_(content_rect),
         invalid_content_rect_(invalid_content_rect),
         contents_scale_(contents_scale),
         tile_resolution_(tile_resolution),
         layer_id_(layer_id),
         source_prepare_tiles_id_(source_prepare_tiles_id),
         tile_(tile),
         new_content_id_(new_content_id),
         previous_content_id_(previous_content_id),
         resource_content_id_(resource_content_id),
         source_frame_number_(source_frame_number),
-        analyze_picture_(analyze_picture),
         reply_(reply) {}
 
   // Overridden from Task:
   void RunOnWorkerThread() override {
     TRACE_EVENT1("cc", "RasterizerTaskImpl::RunOnWorkerThread",
                  "source_prepare_tiles_id", source_prepare_tiles_id_);
 
     DCHECK(raster_source_.get());
     DCHECK(raster_buffer_);
 
-    if (analyze_picture_) {
-      Analyze(raster_source_.get());
-      if (analysis_.is_solid_color)
-        return;
-    }
-
     Raster(raster_source_.get());
   }
 
   // Overridden from TileTask:
   void ScheduleOnOriginThread(TileTaskClient* client) override {
     DCHECK(!raster_buffer_);
     raster_buffer_ = client->AcquireBufferForRaster(
         resource_, resource_content_id_, previous_content_id_);
   }
   void CompleteOnOriginThread(TileTaskClient* client) override {
     client->ReleaseBufferForRaster(std::move(raster_buffer_));
-    reply_.Run(analysis_, !HasFinishedRunning());
+    reply_.Run(!HasFinishedRunning());
   }
 
  protected:
   ~RasterTaskImpl() override { DCHECK(!raster_buffer_); }
 
  private:
-  void Analyze(const DisplayListRasterSource* raster_source) {
-    frame_viewer_instrumentation::ScopedAnalyzeTask analyze_task(
-        tile_, tile_resolution_, source_frame_number_, layer_id_);
-
-    DCHECK(raster_source);
-
-    raster_source->PerformSolidColorAnalysis(content_rect_, contents_scale_,
-                                             &analysis_);
-    // Clear the flag if we're not using the estimator.
-    analysis_.is_solid_color &= kUseColorEstimator;
-  }
-
   void Raster(const DisplayListRasterSource* raster_source) {
     frame_viewer_instrumentation::ScopedRasterTask raster_task(
         tile_, tile_resolution_, source_frame_number_, layer_id_);
     ScopedRasterTaskTimer timer;
     timer.SetArea(content_rect_.size().GetArea());
 
     DCHECK(raster_source);
 
     bool include_images = tile_resolution_ != LOW_RESOLUTION;
     raster_buffer_->Playback(raster_source_.get(), content_rect_,
                              invalid_content_rect_, new_content_id_,
                              contents_scale_, include_images);
   }
 
   const Resource* resource_;
-  DisplayListRasterSource::SolidColorAnalysis analysis_;
   scoped_refptr<DisplayListRasterSource> raster_source_;
   gfx::Rect content_rect_;
   gfx::Rect invalid_content_rect_;
   float contents_scale_;
   TileResolution tile_resolution_;
   int layer_id_;
   uint64_t source_prepare_tiles_id_;
   const void* tile_;
   uint64_t new_content_id_;
   uint64_t previous_content_id_;
   uint64_t resource_content_id_;
   int source_frame_number_;
-  bool analyze_picture_;
-  const base::Callback<void(const DisplayListRasterSource::SolidColorAnalysis&,
-                            bool)> reply_;
+  const base::Callback<void(bool)> reply_;
   scoped_ptr<RasterBuffer> raster_buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(RasterTaskImpl);
 };
 
 // Task priorities that make sure that the task set done tasks run before any
 // other remaining tasks.
 const size_t kRequiredForActivationDoneTaskPriority = 1u;
 const size_t kRequiredForDrawDoneTaskPriority = 2u;
 const size_t kAllDoneTaskPriority = 3u;
@@ skipping 421 matching lines @@
     Tile* tile = prioritized_tile.tile();
     TilePriority priority = prioritized_tile.priority();
 
     if (TilePriorityViolatesMemoryPolicy(priority)) {
       TRACE_EVENT_INSTANT0(
           "cc", "TileManager::AssignGpuMemory tile violates memory policy",
           TRACE_EVENT_SCOPE_THREAD);
       break;
     }
 
+    if (tile->use_picture_analysis() && kUseColorEstimator) {
+      // We analyze for solid color here, to decide to continue
+      // or drop the tile for scheduling and raster.
+      SkColor color = SK_ColorTRANSPARENT;
+      bool is_solid_color =
+          prioritized_tile.raster_source()->PerformSolidColorAnalysis(

[ericrk, 2016/01/07 18:18:10]

There's a comment in the bug that we might be spending significant time in
canvas creation, and one benefit of moving solid color checks to a tight loop is
that we could use a shared canvas which is reset between checks (rather than
re-created each time). Did you look into this at all? We don't need to address
this now, but might be good to add a TODO to investigate.

[sohanjg, 2016/01/08 11:47:56]

Acknowledged.

+              tile->content_rect(), tile->contents_scale(), &color);
+      if (is_solid_color) {
+        tile->draw_info().set_solid_color(color);

[vmpstr, 2016/01/07 22:36:02]

nit: call tile->draw_info().set_was_ever_ready_to_draw(); please. I think we
also have to call client_->NotifyTileStateChanged(tile);

These are all the functions that would have happened in UpdateTileDrawInfo

[sohanjg, 2016/01/08 11:47:56]

Done.

+        continue;
+      }
+    }
+
     // We won't be able to schedule this tile, so break out early.
     if (tiles_that_need_to_be_rasterized->size() >=
         scheduled_raster_task_limit) {
       all_tiles_that_need_to_be_rasterized_are_scheduled_ = false;
       break;
     }
 
     tile->scheduled_priority_ = schedule_priority++;
 
     DCHECK(tile->draw_info().mode() == TileDrawInfo::OOM_MODE ||
@@ skipping 213 matching lines @@
     decode_tasks.push_back(image_decode_controller_.GetTaskForImage(
         image, tile->layer_id(), prepare_tiles_count_));
   }
 
   return make_scoped_refptr(new RasterTaskImpl(
       resource, prioritized_tile.raster_source(), tile->content_rect(),
       tile->invalidated_content_rect(), tile->contents_scale(),
       prioritized_tile.priority().resolution, tile->layer_id(),
       prepare_tiles_count_, static_cast<const void*>(tile), tile->id(),
       tile->invalidated_id(), resource_content_id, tile->source_frame_number(),
-      tile->use_picture_analysis(),
       base::Bind(&TileManager::OnRasterTaskCompleted, base::Unretained(this),
                  tile->id(), resource),
       &decode_tasks));
 }
 
 void TileManager::OnRasterTaskCompleted(
     Tile::Id tile_id,
     Resource* resource,
-    const DisplayListRasterSource::SolidColorAnalysis& analysis,
     bool was_canceled) {
   DCHECK(tiles_.find(tile_id) != tiles_.end());
 
   Tile* tile = tiles_[tile_id];
   DCHECK(tile->raster_task_.get());
   orphan_tasks_.push_back(tile->raster_task_);
   tile->raster_task_ = nullptr;
 
   if (was_canceled) {
     ++flush_stats_.canceled_count;
     // TODO(ericrk): If more partial raster work is done in the future, it may
     // be worth returning the resource to the pool with its previous ID (not
     // currently tracked). crrev.com/1370333002/#ps40001 has a possible method
     // of achieving this.
     resource_pool_->ReleaseResource(resource, 0 /* content_id */);
     return;
   }
 
-  UpdateTileDrawInfo(tile, resource, analysis);
+  UpdateTileDrawInfo(tile, resource);

[vmpstr, 2016/01/07 22:36:02]

nit: since a lot of the logic of UpdateTileDrawInfo is gone, maybe we can just
move the code here and delete the function. Up to you if you think it's worth
it.

[sohanjg, 2016/01/08 11:47:56]

Done.

 }
 
-void TileManager::UpdateTileDrawInfo(
-    Tile* tile,
-    Resource* resource,
-    const DisplayListRasterSource::SolidColorAnalysis& analysis) {
+void TileManager::UpdateTileDrawInfo(Tile* tile, Resource* resource) {
   TileDrawInfo& draw_info = tile->draw_info();
 
   ++flush_stats_.completed_count;
 
-  if (analysis.is_solid_color) {
-    draw_info.set_solid_color(analysis.solid_color);
-    if (resource) {
-      // TODO(ericrk): If more partial raster work is done in the future, it may
-      // be worth returning the resource to the pool with its previous ID (not
-      // currently tracked). crrev.com/1370333002/#ps40001 has a possible method
-      // of achieving this.
-      resource_pool_->ReleaseResource(resource, 0 /* content_id */);
-    }
-  } else {
-    DCHECK(resource);
-    draw_info.set_use_resource();
-    draw_info.resource_ = resource;
-    draw_info.contents_swizzled_ = DetermineResourceRequiresSwizzle(tile);
-  }
+  DCHECK(resource);
+  draw_info.set_use_resource();
+  draw_info.resource_ = resource;
+  draw_info.contents_swizzled_ = DetermineResourceRequiresSwizzle(tile);
+
   DCHECK(draw_info.IsReadyToDraw());
   draw_info.set_was_ever_ready_to_draw();
 
   client_->NotifyTileStateChanged(tile);
 }
 
 ScopedTilePtr TileManager::CreateTile(const Tile::CreateInfo& info,
                                       int layer_id,
                                       int source_frame_number,
                                       int flags) {
@@ skipping 278 matching lines @@
 void TileManager::Signals::reset() {
   ready_to_activate = false;
   did_notify_ready_to_activate = false;
   ready_to_draw = false;
   did_notify_ready_to_draw = false;
   all_tile_tasks_completed = false;
   did_notify_all_tile_tasks_completed = false;
 }
 
 }  // namespace cc