Update from https://crrev.com/306706

cc/resources/picture_pile.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/resources/picture_pile.h"
 
 #include <algorithm>
 #include <limits>
 #include <vector>
 
@@ skipping 538 matching lines @@
 
     for (int i = 0; i < repeat_count; i++) {
       picture = Picture::Create(padded_record_rect, painter, tile_grid_info_,
                                 gather_pixel_refs, recording_mode);
       // Note the '&&' with previous is-suitable state.
       // This means that once a picture-pile becomes unsuitable for gpu
       // rasterization due to some content, it will continue to be unsuitable
       // even if that content is replaced by gpu-friendly content.
       // This is an optimization to avoid iterating though all pictures in
       // the pile after each invalidation.
-      is_suitable_for_gpu_rasterization_ &=
-          picture->IsSuitableForGpuRasterization();
+      if (is_suitable_for_gpu_rasterization_) {
+        const char* reason = nullptr;
+        is_suitable_for_gpu_rasterization_ &=
+            picture->IsSuitableForGpuRasterization(&reason);
+
+        if (!is_suitable_for_gpu_rasterization_) {
+          TRACE_EVENT_INSTANT1("cc", "GPU Rasterization Veto",
+                               TRACE_EVENT_SCOPE_THREAD, "reason", reason);
+        }
+      }
     }
 
     bool found_tile_for_recorded_picture = false;
 
     bool include_borders = true;
     for (TilingData::Iterator it(&tiling_, padded_record_rect, include_borders);
          it; ++it) {
       const PictureMapKey& key = it.index();
       gfx::Rect tile = PaddedRect(key);
       if (padded_record_rect.Contains(tile)) {
@@ skipping 192 matching lines @@
 const Picture* PicturePile::PictureInfo::GetPicture() const {
   return picture_.get();
 }
 
 float PicturePile::PictureInfo::GetInvalidationFrequency() const {
   return invalidation_history_.count() /
          static_cast<float>(INVALIDATION_FRAMES_TRACKED);
 }
 
 }  // namespace cc