Ink drops with touch input are redundant on Windows since the OS does something similar

ui/views/animation/ink_drop_host_view.cc

Index: ui/views/animation/ink_drop_host_view.cc
diff --git a/ui/views/animation/ink_drop_host_view.cc b/ui/views/animation/ink_drop_host_view.cc
index e6b1e424155d41e75056cdf1744fc2e7e2684fcc..fdfc7c7fb8f2bff62ff3a7936fe05bbaae538856 100644
--- a/ui/views/animation/ink_drop_host_view.cc
+++ b/ui/views/animation/ink_drop_host_view.cc
@@ -172,6 +172,24 @@ gfx::Point InkDropHostView::GetInkDropCenterBasedOnLastEvent() const {
 
 void InkDropHostView::AnimateInkDrop(InkDropState state,
                                      const ui::LocatedEvent* event) {
+#if defined(OS_WIN)
+  // On Windows, don't initiate ink-drops. Additionally, certain event states
+  // should dismiss existing ink-drop animations.
+  if (event && event->IsGestureEvent()) {
+    // Don't transtion the ink-drop to a "pending" state from a touch event.

[Evan Stade, 2016/06/27 16:42:51]

nit: sp (transition)

+    if (state == InkDropState::ACTION_PENDING ||
+        state == InkDropState::ALTERNATE_ACTION_PENDING)
+      return;
+    // If the state is already pending, presumably from a mouse or keyboard
+    // event, then a "triggered" action state should be allowed. Conversely,
+    // if the state had already transitioned to hidden, then the touch event
+    // is ignored.
+    if ((state == InkDropState::ACTION_TRIGGERED ||
+         state == InkDropState::ALTERNATE_ACTION_TRIGGERED) &&
+        ink_drop_->GetTargetInkDropState() == InkDropState::HIDDEN)
+      return;
+  }
+#endif
   last_ripple_triggering_event_.reset(
       event ? ui::Event::Clone(*event).release()->AsLocatedEvent() : nullptr);
   ink_drop_->AnimateToState(state);