Create a unified UIElement interface for Widget, View and Window.

ash/common/devtools/ash_devtools_unittest.cc

Index: ash/common/devtools/ash_devtools_unittest.cc
diff --git a/ash/common/devtools/ash_devtools_unittest.cc b/ash/common/devtools/ash_devtools_unittest.cc
index 4ae947a357fe79d59fb225e572ad346c0ebcd7a4..837134f874f0f6c5ea2c050d1bf0a722c94f5227 100644
--- a/ash/common/devtools/ash_devtools_unittest.cc
+++ b/ash/common/devtools/ash_devtools_unittest.cc
@@ -42,6 +42,7 @@ class FakeFrontendChannel : public FrontendChannel {
   int CountProtocolNotificationMessageStartsWith(const std::string& message) {
     int count = 0;
     for (const std::string& s : protocol_notification_messages_) {
+      LOG(ERROR) << "CountProtocolNotificationMessageStartsWith: " << s;
       if (base::StartsWith(s, message, base::CompareCase::SENSITIVE))
         count++;
     }
@@ -59,6 +60,8 @@ class FakeFrontendChannel : public FrontendChannel {
   void flushProtocolNotifications() override {}
   void sendProtocolNotification(
       std::unique_ptr<Serializable> message) override {
+    LOG(ERROR) << "---------- protocol_notification_messages_.size(): "
+               << protocol_notification_messages_.size();
     protocol_notification_messages_.push_back(message->serialize());
   }