cc: Do solid color analysis before scheduling tiles.

cc/tiles/tile_manager.cc

Index: cc/tiles/tile_manager.cc
diff --git a/cc/tiles/tile_manager.cc b/cc/tiles/tile_manager.cc
index 400fff20646bf77374fab31801f7181d207551f6..21df67df1dde7ca912887712eb517a240ffa9be5 100644
--- a/cc/tiles/tile_manager.cc
+++ b/cc/tiles/tile_manager.cc
@@ -55,10 +55,7 @@ class RasterTaskImpl : public RasterTask {
                  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),
@@ -74,7 +71,6 @@ class RasterTaskImpl : public RasterTask {
         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:
@@ -85,12 +81,6 @@ class RasterTaskImpl : public RasterTask {
     DCHECK(raster_source_.get());
     DCHECK(raster_buffer_);
 
-    if (analyze_picture_) {
-      Analyze(raster_source_.get());
-      if (analysis_.is_solid_color)
-        return;
-    }
-
     Raster(raster_source_.get());
   }
 
@@ -102,25 +92,13 @@ class RasterTaskImpl : public RasterTask {
   }
   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_);
@@ -136,7 +114,6 @@ class RasterTaskImpl : public RasterTask {
   }
 
   const Resource* resource_;
-  DisplayListRasterSource::SolidColorAnalysis analysis_;
   scoped_refptr<DisplayListRasterSource> raster_source_;
   gfx::Rect content_rect_;
   gfx::Rect invalid_content_rect_;
@@ -149,9 +126,7 @@ class RasterTaskImpl : public RasterTask {
   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);
@@ -593,6 +568,19 @@ void TileManager::AssignGpuMemoryToTiles(
       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) {
@@ -826,7 +814,6 @@ scoped_refptr<RasterTask> TileManager::CreateRasterTask(
       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));
@@ -835,7 +822,6 @@ scoped_refptr<RasterTask> TileManager::CreateRasterTask(
 void TileManager::OnRasterTaskCompleted(
     Tile::Id tile_id,
     Resource* resource,
-    const DisplayListRasterSource::SolidColorAnalysis& analysis,
     bool was_canceled) {
   DCHECK(tiles_.find(tile_id) != tiles_.end());
 
@@ -854,32 +840,19 @@ void TileManager::OnRasterTaskCompleted(
     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();