cc: Implement overdraw feedback debugging feature.

cc/output/gl_renderer.h

 // 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.
 
 #ifndef CC_OUTPUT_GL_RENDERER_H_
 #define CC_OUTPUT_GL_RENDERER_H_
 
 #include <deque>
+#include <set>
 #include <vector>
 
 #include "base/cancelable_callback.h"
 #include "base/macros.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/color_lut_cache.h"
 #include "cc/output/context_cache_controller.h"
 #include "cc/output/direct_renderer.h"
 #include "cc/output/gl_renderer_draw_cache.h"
 #include "cc/output/program_binding.h"
@@ skipping 244 matching lines @@
       const CALayerOverlay* ca_layer_overlay,
       Resource** resource,
       DrawingFrame* frame,
       gfx::RectF* new_bounds);
 
   // Schedules the |ca_layer_overlay|, which is guaranteed to have a non-null
   // |rpdq| parameter.
   void ScheduleRenderPassDrawQuad(const CALayerOverlay* ca_layer_overlay,
                                   DrawingFrame* external_frame);
 
+  // Setup/flush all pending overdraw feedback to framebuffer.
+  void SetupOverdrawFeedback();
+  void FlushOverdrawFeedback(const DrawingFrame* frame,
+                             const gfx::Rect& output_rect);
+  // Process overdraw feedback from query.
+  void OverdrawFeedback(unsigned query, int category, base::Closure barrier);
+  void UpdateOverdrawCounter() const;
+
   using OverlayResourceLock =
       std::unique_ptr<ResourceProvider::ScopedReadLockGL>;
   using OverlayResourceLockList = std::vector<OverlayResourceLock>;
 
   // Resources that have been sent to the GPU process, but not yet swapped.
   OverlayResourceLockList pending_overlay_resources_;
 
   // Resources that should be shortly swapped by the GPU process.
   std::deque<OverlayResourceLockList> swapping_overlay_resources_;
 
@@ skipping 253 matching lines @@
 
   // The method FlippedFramebuffer determines whether the framebuffer associated
   // with a DrawingFrame is flipped. It makes the assumption that the
   // DrawingFrame is being used as part of a render pass. If a DrawingFrame is
   // not being used as part of a render pass, setting it here forces
   // FlippedFramebuffer to return |true|.
   bool force_drawing_frame_framebuffer_unflipped_ = false;
 
   BoundGeometry bound_geometry_;
   ColorLUTCache color_lut_cache_;
+
+  std::set<int> current_overdraw_;

[danakj, 2017/01/12 00:42:58]

set is very slow, is there a better structure you can use?

[reveman, 2017/01/13 01:27:43]

FYI, this will become a map in a follow up patch where we track the exact amount
of overdraw.

I think set/map is fine. It makes for clean and easy to read code and it's only
used when overdraw tracing is enabled so it doesn't effect normal chrome
performance.

+  unsigned offscreen_stencil_renderbuffer_id_ = 0;
+  gfx::Size offscreen_stencil_renderbuffer_size_;
+  struct PendingOverdrawQuery;
+  std::deque<std::unique_ptr<PendingOverdrawQuery>> pending_overdraw_queries_;

[danakj, 2017/01/12 00:42:58]

deque is very costly for memory
https://bugs.chromium.org/p/chromium/issues/detail?id=674287 is there something
better you can use?

[reveman, 2017/01/13 01:27:43]

Removed this completely from latest version of the patch.

+
   DISALLOW_COPY_AND_ASSIGN(GLRenderer);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_GL_RENDERER_H_