Support targeting for gestures in ViewTargeter

ui/views/view_targeter.cc

Index: ui/views/view_targeter.cc
diff --git a/ui/views/view_targeter.cc b/ui/views/view_targeter.cc
index 99c28fe78755440bd24d4d3b046198fab9a6d212..a0dcbe0a17cb596b293ce632ed1131f92a0f5b0d 100644
--- a/ui/views/view_targeter.cc
+++ b/ui/views/view_targeter.cc
@@ -39,6 +39,9 @@ ui::EventTarget* ViewTargeter::FindTargetForEvent(ui::EventTarget* root,
                                     *static_cast<ui::ScrollEvent*>(event));
   }
 
+  if (event->IsGestureEvent())
+    return FindTargetForGestureEvent(view, *(event->AsGestureEvent()));
+
   NOTREACHED() << "ViewTargeter does not yet support this event type.";
   return NULL;
 }
@@ -46,6 +49,14 @@ ui::EventTarget* ViewTargeter::FindTargetForEvent(ui::EventTarget* root,
 ui::EventTarget* ViewTargeter::FindNextBestTarget(
     ui::EventTarget* previous_target,
     ui::Event* event) {
+  if (!previous_target)
+    return NULL;
+
+  if (event->IsGestureEvent()) {
+    return FindNextBestTargetForGestureEvent(previous_target,
+                                             *(event->AsGestureEvent()));
+  }
+
   return previous_target->GetParentTarget();
 }
 
@@ -75,4 +86,22 @@ View* ViewTargeter::FindTargetForScrollEvent(View* root,
   return root->GetEffectiveViewTargeter()->TargetForRect(root, rect);
 }
 
+View* ViewTargeter::FindTargetForGestureEvent(View* root,
+                                              const ui::GestureEvent& gesture) {
+  // TODO(tdanderson): The only code path that performs targeting for gestures
+  //                   uses the ViewTargeter installed on the RootView (i.e.,
+  //                   a RootViewTargeter). Provide a default implementation
+  //                   here if we need to be able to perform gesture targeting
+  //                   starting at an arbitrary node in a Views tree.
+  NOTREACHED();
+  return NULL;
+}
+
+ui::EventTarget* ViewTargeter::FindNextBestTargetForGestureEvent(
+    ui::EventTarget* previous_target,
+    const ui::GestureEvent& gesture) {
+  NOTREACHED();
+  return NULL;
+}
+
 }  // namespace views