Move compositor InputHandler from RenderViewImpl to RenderWidget.

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 2977 matching lines @@
   bool is_viewport_scroll_layer =
       viewport()->MainScrollLayer() &&
       scroll_node->owning_layer_id == viewport()->MainScrollLayer()->id();
 
   // This is needed if the scroll chains up to the viewport without going
   // through the outer viewport scroll layer. This can happen if we scroll an
   // element that's not a descendant of the document.rootScroller. In that case
   // we want to scroll the inner viewport -- to allow panning while zoomed --
   // but also move browser controls if needed.
   bool is_inner_viewport_scroll_layer =
+      InnerViewportScrollLayer() &&
       scroll_node->owning_layer_id == InnerViewportScrollLayer()->id();
 
   if (is_viewport_scroll_layer || is_inner_viewport_scroll_layer) {
     Viewport::ScrollResult result = viewport()->ScrollBy(
         delta, viewport_point, scroll_state->is_direct_manipulation(),
         !wheel_scrolling_, is_viewport_scroll_layer);
 
     applied_delta = result.consumed_delta;
     delta_applied_to_content = result.content_scrolled_delta;
   } else {
@@ skipping 1084 matching lines @@
       worker_context_visibility_ =
           worker_context->CacheController()->ClientBecameVisible();
     } else {
       worker_context->CacheController()->ClientBecameNotVisible(
           std::move(worker_context_visibility_));
     }
   }
 }
 
 }  // namespace cc