cc: optimize color matrix application for more complex filter DAGs.

cc/output/gl_renderer.cc

 // Copyright 2010 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/output/gl_renderer.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 990 matching lines @@
   bool use_color_matrix = false;
   gfx::RectF rect = gfx::RectF(quad->rect);
   if (!quad->filters.IsEmpty()) {
     sk_sp<SkImageFilter> filter = RenderSurfaceFilters::BuildImageFilter(
         quad->filters, gfx::SizeF(contents_texture->size()));
     if (filter) {
       SkColorFilter* colorfilter_rawptr = NULL;
       filter->asColorFilter(&colorfilter_rawptr);
       sk_sp<SkColorFilter> cf(colorfilter_rawptr);
 
-      if (cf && cf->asColorMatrix(color_matrix) && !filter->getInput(0)) {
-        // We have a single color matrix as a filter; apply it locally
-        // in the compositor.
+      if (cf && cf->asColorMatrix(color_matrix)) {
+        // We have a color matrix at the root of the filter DAG; apply it
+        // locally in the compositor and process the rest of the DAG (if any)
+        // in Skia.
         use_color_matrix = true;
-      } else {
+        filter = sk_ref_sp(filter->getInput(0));
+      }
+      if (filter) {
         gfx::Vector2dF scale = quad->filters_scale;
         SkMatrix scale_matrix;
         scale_matrix.setScale(scale.x(), scale.y());
         SkIRect result_rect =
             filter->filterBounds(gfx::RectToSkIRect(quad->rect), scale_matrix,
                                  SkImageFilter::kForward_MapDirection);
         gfx::RectF dst_rect = gfx::SkRectToRectF(SkRect::Make(result_rect));
         // If the destination rect is not the same as the source rect, the edges
         // previously computed for AA will be wrong. Rather than recompute them
         // here, disable antialiasing and use a 1-pixel transparent
@@ skipping 2635 matching lines @@
       texture_id = pending_overlay_resources_.back()->texture_id();
     }
 
     context_support_->ScheduleOverlayPlane(
         overlay.plane_z_order, overlay.transform, texture_id,
         ToNearestRect(overlay.display_rect), overlay.uv_rect);
   }
 }
 
 }  // namespace cc