Add an explicit ObjectWatcher::IsWatching() method

base/win/object_watcher_unittest.cc

Index: base/win/object_watcher_unittest.cc
diff --git a/base/win/object_watcher_unittest.cc b/base/win/object_watcher_unittest.cc
index 46b98de524d3fd7af4789a93eda4f7fe2355cb4c..1a5e9e2a1a73e124e983c851b8b6cce5ea82dd82 100644
--- a/base/win/object_watcher_unittest.cc
+++ b/base/win/object_watcher_unittest.cc
@@ -37,7 +37,7 @@ void RunTest_BasicSignal(MessageLoop::Type message_loop_type) {
   MessageLoop message_loop(message_loop_type);
 
   ObjectWatcher watcher;
-  EXPECT_EQ(NULL, watcher.GetWatchedObject());
+  EXPECT_FALSE(watcher.IsWatching());
 
   // A manual-reset event that is not yet signaled.
   HANDLE event = CreateEvent(NULL, TRUE, FALSE, NULL);
@@ -45,13 +45,14 @@ void RunTest_BasicSignal(MessageLoop::Type message_loop_type) {
   QuitDelegate delegate;
   bool ok = watcher.StartWatching(event, &delegate);
   EXPECT_TRUE(ok);
+  EXPECT_TRUE(watcher.IsWatching());
   EXPECT_EQ(event, watcher.GetWatchedObject());
 
   SetEvent(event);
 
   MessageLoop::current()->Run();
 
-  EXPECT_EQ(NULL, watcher.GetWatchedObject());
+  EXPECT_FALSE(watcher.IsWatching());
   CloseHandle(event);
 }
 
@@ -115,7 +116,7 @@ void RunTest_SignalBeforeWatch(MessageLoop::Type message_loop_type) {
 
   MessageLoop::current()->Run();
 
-  EXPECT_EQ(NULL, watcher.GetWatchedObject());
+  EXPECT_FALSE(watcher.IsWatching());
   CloseHandle(event);
 }