[Views] Update ink drop for omnibox icons

ui/views/animation/ink_drop.cc

Index: ui/views/animation/ink_drop.cc
diff --git a/ui/views/animation/ink_drop.cc b/ui/views/animation/ink_drop.cc
index 6a1df9896c7f074d76645933d291b1ae052497c6..6d971090ae3bd6c2d24b9435c173e3cfb4517feb 100644
--- a/ui/views/animation/ink_drop.cc
+++ b/ui/views/animation/ink_drop.cc
@@ -4,8 +4,29 @@
 
 #include "ui/views/animation/ink_drop.h"
 
+#include "ui/views/animation/ink_drop_observer.h"
+
 namespace views {
 
+InkDrop::~InkDrop() {}
+
+void InkDrop::AddObserver(InkDropObserver* observer) {
+  CHECK(observer);
+  observers_.AddObserver(observer);
+}
+
+void InkDrop::RemoveObserver(InkDropObserver* observer) {
+  CHECK(observer);
+  observers_.RemoveObserver(observer);
+}
+
+InkDrop::InkDrop() {}
+
+void InkDrop::NotifyInkDropAnimationStarted() {
+  for (InkDropObserver& observer : observers_)
+    observer.InkDropAnimationStarted();
+}
+
 InkDropContainerView::InkDropContainerView() {}
 
 void InkDropContainerView::AddInkDropLayer(ui::Layer* ink_drop_layer) {