Disable the direct-drawing optimization for quads with opacity.

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 983 matching lines @@
   // and has the same size as the pass.
   if (!quad->shared_quad_state->quad_to_target_transform.IsIdentity() ||
       quad->rect != pass->output_rect)
     return nullptr;
   // The quad is expected to be the entire layer so that AA edges are correct.
   if (gfx::Rect(quad->shared_quad_state->quad_layer_bounds) != quad->rect)
     return nullptr;
   if (quad->material != DrawQuad::TILED_CONTENT)
     return nullptr;
 
+  // TODO(chrishtr): support could be added for opacity, but care needs
+  // to be taken to make sure it is correct w.r.t. non-commutative filters etc.
+  if (quad->shared_quad_state->opacity != 1.0f)
+    return nullptr;
+
   const TileDrawQuad* tile_quad = TileDrawQuad::MaterialCast(quad);
   // Hack: this could be supported by passing in a subrectangle to draw
   // render pass, although in practice if there is only one quad there
   // will be no border texels on the input.
   if (tile_quad->tex_coord_rect != gfx::RectF(tile_quad->rect))
     return nullptr;
   // Tile quad features not supported in render pass shaders.
   if (tile_quad->swizzle_contents || tile_quad->nearest_neighbor)
     return nullptr;
   // BUG=skia:3868, Skia currently doesn't support texture rectangle inputs.
@@ skipping 2492 matching lines @@
     return;
 
   // Report GPU overdraw as a percentage of |max_result|.
   TRACE_COUNTER1(
       TRACE_DISABLED_BY_DEFAULT("cc.debug.overdraw"), "GPU Overdraw",
       (std::accumulate(overdraw->begin(), overdraw->end(), 0) * 100) /
           max_result);
 }
 
 }  // namespace cc