cc: Do not allow gesture-scrolling 'overflow[-{x|y}]:hidden' layers.

cc/layers/layer.cc

 // Copyright 2010 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.h"
 
 #include <algorithm>
 
 #include "base/debug/trace_event.h"
 #include "base/location.h"
@@ skipping 23 matching lines @@
     : needs_push_properties_(false),
       num_dependents_need_push_properties_(false),
       stacking_order_changed_(false),
       layer_id_(s_next_layer_id++),
       ignore_set_needs_commit_(false),
       parent_(NULL),
       layer_tree_host_(NULL),
       scrollable_(false),
       should_scroll_on_main_thread_(false),
       have_wheel_event_handlers_(false),
+      user_scrollable_horizontal_(true),
+      user_scrollable_vertical_(true),
       anchor_point_(0.5f, 0.5f),
       background_color_(0),
       compositing_reasons_(kCompositingReasonUnknown),
       opacity_(1.f),
       anchor_point_z_(0.f),
       is_container_for_fixed_position_layers_(false),
       is_drawable_(false),
       hide_layer_and_subtree_(false),
       masks_to_bounds_(false),
       contents_opaque_(false),
@@ skipping 772 matching lines @@
   layer->SetFixedContainerSizeDelta(gfx::Vector2dF());
   layer->SetPositionConstraint(position_constraint_);
   layer->SetPreserves3d(preserves_3d());
   layer->SetUseParentBackfaceVisibility(use_parent_backface_visibility_);
   layer->SetSublayerTransform(sublayer_transform_);
   if (!layer->TransformIsAnimatingOnImplOnly() && !TransformIsAnimating())
     layer->SetTransform(transform_);
   DCHECK(!(TransformIsAnimating() && layer->TransformIsAnimatingOnImplOnly()));
 
   layer->SetScrollable(scrollable_);
+  layer->SetUserScrollable(user_scrollable_horizontal_,
+                           user_scrollable_vertical_);
   layer->SetMaxScrollOffset(max_scroll_offset_);
 
   LayerImpl* scroll_parent = NULL;
   if (scroll_parent_)
     scroll_parent = layer->layer_tree_impl()->LayerById(scroll_parent_->id());
 
   layer->SetScrollParent(scroll_parent);
   if (scroll_children_) {
     std::set<LayerImpl*>* scroll_children = new std::set<LayerImpl*>;
     for (std::set<Layer*>::iterator it = scroll_children_->begin();
@@ skipping 238 matching lines @@
     clip_parent_->RemoveClipChild(this);
 
   clip_parent_ = NULL;
 }
 
 void Layer::RunMicroBenchmark(MicroBenchmark* benchmark) {
   benchmark->RunOnLayer(this);
 }
 
 }  // namespace cc