cc: Disable checker-imaging for decode=async tag.

Temporarily disabling checkering of decode=async tag images to debug
entries in ukm logs for checkerboarded images in the control group for
checkerimaging finch study.

R=vmpstr@chromium.org

Bug: 833666
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Ib9a79262599efa17fd18e9cb71d7518492e9a7ee
Reviewed-on: https://chromium-review.googlesource.com/1014644Reviewed-by: vmpstr <vmpstr@chromium.org>
Commit-Queue: Khushal <khushalsagar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551513}

cc/tiles/checker_image_tracker.cc

@@ -286,8 +286,9 @@ bool CheckerImageTracker::ShouldCheckerImage(const DrawImage& draw_image,
   // specify "async" then we don't checker the images. To put it different, we
   // currently only not respect |enable_checker_imaging_| if the value was
   // specified as "async" by the developer.
-  if (decoding_mode_hint != PaintImage::DecodingMode::kAsync &&
-      !enable_checker_imaging_) {
+  // TODO(khushalsagar): Enable this for async decode hint images. Temporarily
+  // disabling for debugging crbug.com/833666.
+  if (!enable_checker_imaging_) {
     return false;
   }
 

cc/trees/layer_tree_host_impl.cc

@@ -414,6 +414,7 @@ void LayerTreeHostImpl::UpdateSyncTreeAfterCommitOrImplSideInvalidation() {
   // and the updated data for the image from the main frame.
     PaintImageIdFlatSet images_to_invalidate =
         tile_manager_.TakeImagesToInvalidateOnSyncTree();
+    CHECK(images_to_invalidate.empty() || settings_.enable_checker_imaging);
     if (ukm_manager_)
       ukm_manager_->AddCheckerboardedImages(images_to_invalidate.size());