Correctly handle damage involving filters in SurfaceAggregator

cc/output/direct_renderer.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/output/direct_renderer.h"
 
 #include <stddef.h>
 
 #include <unordered_map>
 #include <utility>
@@ skipping 260 matching lines @@
   } else {
     DrawRenderPassAndExecuteCopyRequests(&frame, root_render_pass);
   }
 
   FinishDrawingFrame(&frame);
   render_passes_in_draw_order->clear();
 }
 
 gfx::Rect DirectRenderer::ComputeScissorRectForRenderPass(
     const DrawingFrame* frame) {
-  gfx::Rect render_pass_scissor = frame->current_render_pass->output_rect;
-
-  if (frame->root_damage_rect == frame->root_render_pass->output_rect ||
-      !frame->current_render_pass->copy_requests.empty())
-    return render_pass_scissor;
-
-  gfx::Transform inverse_transform(gfx::Transform::kSkipInitialization);
-  if (frame->current_render_pass->transform_to_root_target.GetInverse(
-          &inverse_transform)) {
-    // Only intersect inverse-projected damage if the transform is invertible.
-    gfx::Rect damage_rect_in_render_pass_space =
-        MathUtil::ProjectEnclosingClippedRect(inverse_transform,
-                                              frame->root_damage_rect);
-    render_pass_scissor.Intersect(damage_rect_in_render_pass_space);
-  }
-
-  return render_pass_scissor;
+  DCHECK(frame->current_render_pass->copy_requests.empty() ||
+         (frame->current_render_pass->damage_rect ==
+          frame->current_render_pass->output_rect));
+  return frame->current_render_pass->damage_rect;
 }
 
 bool DirectRenderer::NeedDeviceClip(const DrawingFrame* frame) const {
   if (frame->current_render_pass != frame->root_render_pass)
     return false;
 
   return !frame->device_clip_rect.Contains(frame->device_viewport_rect);
 }
 
 gfx::Rect DirectRenderer::DeviceClipRectInDrawSpace(
@@ skipping 256 matching lines @@
   auto iter = render_pass_textures_.find(id);
   return iter != render_pass_textures_.end() && iter->second->id();
 }
 
 // static
 gfx::Size DirectRenderer::RenderPassTextureSize(const RenderPass* render_pass) {
   return render_pass->output_rect.size();
 }
 
 }  // namespace cc