Pushed InkDropHost inheritence up to CustomButton.

ui/views/animation/ink_drop_host.cc

Index: ui/views/animation/ink_drop_host.cc
diff --git a/ui/views/animation/ink_drop_host.cc b/ui/views/animation/ink_drop_host.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b86617ad99781db1062335f383d58877adf4d7c9
--- /dev/null
+++ b/ui/views/animation/ink_drop_host.cc
@@ -0,0 +1,17 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/views/animation/ink_drop_host.h"
+
+namespace views {
+
+InkDropHost::InkDropHost() {}
+
+InkDropHost::~InkDropHost() {}
+
+void InkDropHost::AddInkDropLayer(ui::Layer* ink_drop_layer) {}
+
+void InkDropHost::RemoveInkDropLayer(ui::Layer* ink_drop_layer) {}

[Evan Stade, 2015/12/29 23:03:37]

p.s. why did you add this default impl instead of making CustomButton have a
default do-nothing impl? pure virtual is generally preferable

[Evan Stade, 2015/12/29 23:06:56]

ah, I see this was suggested by Peter. I prefer pure virtual in this situation,
but perhaps it's a policy decision that has been made at a broader level. It
seems like the Google C++ style guide forbids multiple inheritance (excluding
pure virtual interfaces), but admittedly that's not followed everywhere in
Chrome.

+
+}  // namespace views