[Android] Disable pull-to-refresh with overflow:hidden

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 86401a7dca992c469fca2e80606a9aeac99ff513..7343cb3475a3e8490a3933c9a6327fe9bff464b7 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -1446,6 +1446,16 @@ CompositorFrameMetadata LayerTreeHostImpl::MakeCompositorFrameMetadata() const {
   active_tree_->GetViewportSelection(&metadata.selection_start,
                                      &metadata.selection_end);
 
+  LayerImpl* root_layer_for_overflow = OuterViewportScrollLayer()
+                                           ? OuterViewportScrollLayer()
+                                           : InnerViewportScrollLayer();
+  if (root_layer_for_overflow) {
+    metadata.root_overflow_x_hidden =
+        !root_layer_for_overflow->user_scrollable_horizontal();
+    metadata.root_overflow_y_hidden =
+        !root_layer_for_overflow->user_scrollable_vertical();
+  }
+
   if (!InnerViewportScrollLayer())
     return metadata;
 
@@ -2664,13 +2674,26 @@ InputHandlerScrollResult LayerTreeHostImpl::ScrollBy(
         unused_root_delta.set_x(0.0f);
       if (std::abs(unused_root_delta.y()) < kEpsilon)
         unused_root_delta.set_y(0.0f);
+
+      // If there is unconsumed scroll after application to the viewport, and
+      // the (outer) viewport layer is explicitly marked unscrollable, suppress
+      // any overscroll, preventing bubbling to UI layers.
+      const LayerImpl* layer_for_user_scrollable_testing =

[jdduke (slow), 2015/02/11 22:22:56]

Oops, I'll go ahead and revert this change, it's not necessary for the patch.

+          OuterViewportScrollLayer() ? OuterViewportScrollLayer() : layer_impl;
+      if (unused_root_delta.x() &&
+          !layer_for_user_scrollable_testing->user_scrollable_horizontal()) {
+        unused_root_delta.set_x(0);
+      }
+      if (unused_root_delta.y() &&
+          !layer_for_user_scrollable_testing->user_scrollable_vertical()) {
+        unused_root_delta.set_y(0);
+      }
+
       // Disable overscroll on axes which is impossible to scroll.
       if (settings_.report_overscroll_only_for_scrollable_axes) {
-        if (std::abs(active_tree_->TotalMaxScrollOffset().x()) <= kEpsilon ||
-            !layer_impl->user_scrollable_horizontal())
+        if (std::abs(active_tree_->TotalMaxScrollOffset().x()) <= kEpsilon)
           unused_root_delta.set_x(0.0f);
-        if (std::abs(active_tree_->TotalMaxScrollOffset().y()) <= kEpsilon ||
-            !layer_impl->user_scrollable_vertical())
+        if (std::abs(active_tree_->TotalMaxScrollOffset().y()) <= kEpsilon)
           unused_root_delta.set_y(0.0f);
       }
     }