MD Buttons: Don't add layers for hidden -> hidden transitions.

ui/views/animation/ink_drop_impl_unittest.cc

Index: ui/views/animation/ink_drop_impl_unittest.cc
diff --git a/ui/views/animation/ink_drop_impl_unittest.cc b/ui/views/animation/ink_drop_impl_unittest.cc
index b7c85dcf28b500ed309aefd24f3ed61341f0d440..5047ffc1f66bccd33dcfc57d09f5754c354a10f6 100644
--- a/ui/views/animation/ink_drop_impl_unittest.cc
+++ b/ui/views/animation/ink_drop_impl_unittest.cc
@@ -370,4 +370,17 @@ TEST_F(InkDropImplTest, HighlightCanCoexistWithSnapToActivatedRipple) {
   EXPECT_TRUE(test_api_.IsHighlightFadingInOrVisible());
 }
 
+// Test that (re-)hiding or un-hovering a hidden ink drop doesn't add layers.
+TEST_F(InkDropImplTest, AlwaysHiddenInkDropHasNoLayers) {
+  ink_drop_host_.set_should_show_highlight(true);
+
+  EXPECT_EQ(0, ink_drop_host_.num_ink_drop_layers_added());
+
+  ink_drop_.AnimateToState(InkDropState::HIDDEN);
+  EXPECT_EQ(0, ink_drop_host_.num_ink_drop_layers_added());
+
+  ink_drop_.SetHovered(false);
+  EXPECT_EQ(0, ink_drop_host_.num_ink_drop_layers_added());
+}
+
 }  // namespace views