[Android]Increase Scrollbar fade delay on Resize.

cc/layers/layer_impl.cc

Index: cc/layers/layer_impl.cc
diff --git a/cc/layers/layer_impl.cc b/cc/layers/layer_impl.cc
index 29bdfe778fdf522fc9a3a8f97d74ef4adb90b71c..bc8f8f3b049327e662d3d142d9509f2fee607278 100644
--- a/cc/layers/layer_impl.cc
+++ b/cc/layers/layer_impl.cc
@@ -1275,27 +1275,28 @@ void LayerImpl::SetScrollbarPosition(ScrollbarLayerImplBase* scrollbar_layer,
     current_offset.Scale(layer_tree_impl()->total_page_scale_factor());
   }
 
-  bool scrollbar_needs_animation = false;
-  scrollbar_needs_animation |= scrollbar_layer->SetVerticalAdjust(
+  bool did_scrollbar_position_changed = false;
+  bool did_scrollbar_resize = false;

[aelias_OOO_until_Jul13, 2014/10/03 01:57:53]

Sorry, one more thing.  I just tried it locally and the fade is delayed after
pinches and after some normal scrolls (when the top controls hide), because they
resize the clip layer.  Please make it only use the long fade when the scroll
layer changes size, not when the clip layer does.  You can do that either by
storing the scroll layer size on the scrollbar_layer, or something more like
your original approach of passing a bool to SetScrollbarPosition.

[MuVen, 2014/10/03 13:01:37]

Done.

+  did_scrollbar_position_changed |= scrollbar_layer->SetVerticalAdjust(
       scrollbar_clip_layer->bounds_delta().y());
   if (scrollbar_layer->orientation() == HORIZONTAL) {
     float visible_ratio = clip_rect.width() / scroll_rect.width();
-    scrollbar_needs_animation |=
+    did_scrollbar_position_changed |=
         scrollbar_layer->SetCurrentPos(current_offset.x());
-    scrollbar_needs_animation |=
+    did_scrollbar_resize |=
         scrollbar_layer->SetMaximum(scroll_rect.width() - clip_rect.width());
-    scrollbar_needs_animation |=
+    did_scrollbar_resize |=
         scrollbar_layer->SetVisibleToTotalLengthRatio(visible_ratio);
   } else {
     float visible_ratio = clip_rect.height() / scroll_rect.height();
-    scrollbar_needs_animation |=
+    did_scrollbar_position_changed |=
         scrollbar_layer->SetCurrentPos(current_offset.y());
-    scrollbar_needs_animation |=
+    did_scrollbar_resize |=
         scrollbar_layer->SetMaximum(scroll_rect.height() - clip_rect.height());
-    scrollbar_needs_animation |=
+    did_scrollbar_resize |=
         scrollbar_layer->SetVisibleToTotalLengthRatio(visible_ratio);
   }
-  if (scrollbar_needs_animation) {
+  if (did_scrollbar_position_changed || did_scrollbar_resize) {
     layer_tree_impl()->set_needs_update_draw_properties();
     // TODO(wjmaclean) The scrollbar animator for the pinch-zoom scrollbars
     // should activate for every scroll on the main frame, not just the
@@ -1311,7 +1312,7 @@ void LayerImpl::SetScrollbarPosition(ScrollbarLayerImplBase* scrollbar_layer,
             layer_tree_impl()->min_page_scale_factor()) ||
            !layer_tree_impl()->settings().use_pinch_zoom_scrollbars);
       if (is_animatable_scrollbar)
-        scrollbar_animation_controller_->DidScrollUpdate();
+        scrollbar_animation_controller_->DidScrollUpdate(did_scrollbar_resize);
     }
   }
 }