WIP - compositor worker mega patch.

cc/layers/layer_impl.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/layers/layer_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <utility>
@@ skipping 1546 matching lines @@
     gfx::ScrollOffset current_offset = scroll_offset_->Current(IsActive());
     if (node->data.scroll_offset != current_offset) {
       node->data.scroll_offset = current_offset;
       node->data.needs_local_transform_update = true;
       transform_tree.set_needs_update(true);
     }
   }
 }
 
 void LayerImpl::DidUpdateScrollOffset() {
+  TRACE_EVENT2("compositor-worker,scroll-compensation",
+               "LayerImpl::DidUpdateScrollOffset", "x",
+               scroll_offset_->Current(IsActive()).x(), "y",
+               scroll_offset_->Current(IsActive()).y());
+
   DCHECK(scroll_offset_);
 
   layer_tree_impl()->DidUpdateScrollState(id());
   NoteLayerPropertyChangedForSubtree();
 
   UpdatePropertyTreeScrollOffset();
 
   // Inform the pending twin that a property changed.
   if (layer_tree_impl()->IsActiveTree()) {
     LayerImpl* pending_twin = layer_tree_impl()->FindPendingTreeLayerById(id());
@@ skipping 339 matching lines @@
            .layer_transforms_should_scale_layer_contents) {
     return default_scale;
   }
 
   gfx::Vector2dF transform_scales = MathUtil::ComputeTransform2dScaleComponents(
       DrawTransform(), default_scale);
   return std::max(transform_scales.x(), transform_scales.y());
 }
 
 }  // namespace cc