Made double-tap zoom work in pinch virtual viewport mode (Chromium-side).

cc/trees/layer_tree_host_unittest_no_message_loop.cc

Index: cc/trees/layer_tree_host_unittest_no_message_loop.cc
diff --git a/cc/trees/layer_tree_host_unittest_no_message_loop.cc b/cc/trees/layer_tree_host_unittest_no_message_loop.cc
index 80162187c2590f76286e0a868ee795dcf33faab0..65841c2195680ffe580722ebc33e70d3480045c7 100644
--- a/cc/trees/layer_tree_host_unittest_no_message_loop.cc
+++ b/cc/trees/layer_tree_host_unittest_no_message_loop.cc
@@ -57,6 +57,10 @@ class LayerTreeHostNoMessageLoopTest
   virtual void BeginMainFrame(const BeginFrameArgs& args) OVERRIDE {}
   virtual void DidBeginMainFrame() OVERRIDE {}
   virtual void Layout() OVERRIDE {}
+  virtual void ApplyViewportDeltas(const gfx::Vector2d& inner_delta,
+                                   const gfx::Vector2d& outer_delta,
+                                   float page_scale,
+                                   float top_controls_delta) OVERRIDE {}
   virtual void ApplyViewportDeltas(const gfx::Vector2d& scroll_delta,
                                    float page_scale,
                                    float top_controls_delta) OVERRIDE {}