Move overscroll bounce to impl thread

content/renderer/input/input_handler_proxy.cc

Index: content/renderer/input/input_handler_proxy.cc
diff --git a/content/renderer/input/input_handler_proxy.cc b/content/renderer/input/input_handler_proxy.cc
index d9a34ada63b15efc548b0188ee606161997a3bfb..ab4512daf1d2d239e5f468effe878628e191131f 100644
--- a/content/renderer/input/input_handler_proxy.cc
+++ b/content/renderer/input/input_handler_proxy.cc
@@ -13,6 +13,7 @@
 #include "content/common/input/web_input_event_traits.h"
 #include "content/public/common/content_switches.h"
 #include "content/renderer/input/input_handler_proxy_client.h"
+#include "content/renderer/input/input_scroll_elasticity_controller.h"
 #include "third_party/WebKit/public/platform/Platform.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "ui/events/latency_info.h"
@@ -161,6 +162,18 @@ InputHandlerProxy::InputHandlerProxy(cc::InputHandler* input_handler,
   input_handler_->BindToClient(this);
   smooth_scroll_enabled_ = CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kEnableSmoothScrolling);
+
+#if defined(OS_MACOSX)
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableThreadedEventHandlingMac)) {
+    cc::ScrollElasticityControllerClient* scroll_elasticity_client =
+        input_handler->GetScrollElasticityControllerClient();
+    scroll_elasticity_controller_.reset(new InputScrollElasticityController(
+        scroll_elasticity_client));
+    scroll_elasticity_client->BindToController(
+        scroll_elasticity_controller_.get());
+  }
+#endif
 }
 
 InputHandlerProxy::~InputHandlerProxy() {}