Store non-fast scrollable regions on ScrollNode

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 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/trees/layer_tree_host_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 2485 matching lines @@
   gfx::Transform screen_space_transform =
       scroll_tree.ScreenSpaceTransform(scroll_node->id);
   if (!screen_space_transform.IsInvertible()) {
     TRACE_EVENT0("cc", "LayerImpl::TryScroll: Ignored NonInvertibleTransform");
     scroll_status.thread = InputHandler::SCROLL_IGNORED;
     scroll_status.main_thread_scrolling_reasons =
         MainThreadScrollingReason::kNonInvertibleTransform;
     return scroll_status;
   }
 
-  if (scroll_node->contains_non_fast_scrollable_region) {
+  if (!scroll_node->non_fast_scrollable_region.IsEmpty()) {
     bool clipped = false;
     gfx::Transform inverse_screen_space_transform(
         gfx::Transform::kSkipInitialization);
     if (!screen_space_transform.GetInverse(&inverse_screen_space_transform)) {
       // TODO(shawnsingh): We shouldn't be applying a projection if screen space
       // transform is uninvertible here. Perhaps we should be returning
       // SCROLL_ON_MAIN_THREAD in this case?
     }
 
     gfx::PointF hit_test_point_in_layer_space = MathUtil::ProjectPoint(
         inverse_screen_space_transform, screen_space_point, &clipped);
-    if (!clipped &&
-        active_tree()
-            ->LayerById(scroll_node->owning_layer_id)
-            ->non_fast_scrollable_region()
-            .Contains(gfx::ToRoundedPoint(hit_test_point_in_layer_space))) {
+    if (!clipped && scroll_node->non_fast_scrollable_region.Contains(
+                        gfx::ToRoundedPoint(hit_test_point_in_layer_space))) {
       TRACE_EVENT0("cc",
                    "LayerImpl::tryScroll: Failed NonFastScrollableRegion");
       scroll_status.thread = InputHandler::SCROLL_ON_MAIN_THREAD;
       scroll_status.main_thread_scrolling_reasons =
           MainThreadScrollingReason::kNonFastScrollableRegion;
       return scroll_status;
     }
   }
 
   if (!scroll_node->scrollable) {
@@ skipping 1612 matching lines @@
       worker_context_visibility_ =
           worker_context->CacheController()->ClientBecameVisible();
     } else {
       worker_context->CacheController()->ClientBecameNotVisible(
           std::move(worker_context_visibility_));
     }
   }
 }
 
 }  // namespace cc