Remove GestureEvent interface, and rename GestureEventImpl to GestureEvent.

ash/launcher/launcher_tooltip_manager.cc

Index: ash/launcher/launcher_tooltip_manager.cc
diff --git a/ash/launcher/launcher_tooltip_manager.cc b/ash/launcher/launcher_tooltip_manager.cc
index 04f7fbc15c66d3a65185767c24ba14afa6f714e8..31b17046f2ac53370c1a99b6e52b475f741f6226 100644
--- a/ash/launcher/launcher_tooltip_manager.cc
+++ b/ash/launcher/launcher_tooltip_manager.cc
@@ -339,7 +339,7 @@ ui::TouchStatus LauncherTooltipManager::PreHandleTouchEvent(
 }
 
 ui::GestureStatus LauncherTooltipManager::PreHandleGestureEvent(
-    aura::Window* target, ui::GestureEventImpl* event) {
+    aura::Window* target, ui::GestureEvent* event) {
   if (widget_ && widget_->IsVisible()) {
     // Because this mouse event may arrive to |view_|, here we just schedule
     // the closing event rather than directly calling Close().