Fix the double-tap to click gesture in touch accessibility mode.

ash/root_window_controller.cc

Index: ash/root_window_controller.cc
diff --git a/ash/root_window_controller.cc b/ash/root_window_controller.cc
index 9bc5d4cea68b167ad9c42f585e223b4fd8dbbba0..4f3349afcb78c329a5d3bae8be0aa545b4109126 100644
--- a/ash/root_window_controller.cc
+++ b/ash/root_window_controller.cc
@@ -681,6 +681,14 @@ bool RootWindowController::IsVirtualKeyboardWindow(aura::Window* window) {
   return parent ? parent->Contains(window) : false;
 }
 
+void RootWindowController::SetTouchAccessibilityAnchorPoint(
+    const gfx::Point& anchor_point) {
+#if defined(OS_CHROMEOS)
+  if (touch_exploration_manager_)
+    touch_exploration_manager_->SetTouchAccessibilityAnchorPoint(anchor_point);
+#endif  // defined(OS_CHROMEOS)
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // RootWindowController, private: