cc: Fix bug where tabs have the wrong scale factor

cc/trees/layer_tree_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_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 581 matching lines @@
 
   set_needs_update_draw_properties();
   DidUpdateScrollState(inner_viewport_scroll_layer_id_);
 }
 
 void LayerTreeImpl::SetDeviceScaleFactor(float device_scale_factor) {
   if (device_scale_factor == device_scale_factor_)
     return;
   device_scale_factor_ = device_scale_factor;
 
+  set_needs_update_draw_properties();
   if (IsActiveTree())
     layer_tree_host_impl_->SetFullRootLayerDamage();
 }
 
 SyncedProperty<ScaleGroup>* LayerTreeImpl::page_scale_factor() {
   return page_scale_factor_.get();
 }
 
 const SyncedProperty<ScaleGroup>* LayerTreeImpl::page_scale_factor() const {
   return page_scale_factor_.get();
@@ skipping 1463 matching lines @@
                                                    const gfx::BoxF& box,
                                                    gfx::BoxF* bounds) const {
   *bounds = gfx::BoxF();
   return layer_tree_host_impl_->animation_host()
              ? layer_tree_host_impl_->animation_host()
                    ->TransformAnimationBoundsForBox(layer->id(), box, bounds)
              : true;
 }
 
 }  // namespace cc