Update a bunch of FLAKY_ tests to match current reality

chrome/test/startup/shutdown_test.cc

Index: chrome/test/startup/shutdown_test.cc
diff --git a/chrome/test/startup/shutdown_test.cc b/chrome/test/startup/shutdown_test.cc
index d1c3c8a9adc07af5e4a74b2a4bf701e12fec9d23..c92cc2f0b2291471ce62e2a10306f6bd892c0e9f 100644
--- a/chrome/test/startup/shutdown_test.cc
+++ b/chrome/test/startup/shutdown_test.cc
@@ -122,28 +122,17 @@ TEST_F(ShutdownTest, SimpleUserQuit) {
                   true, /* important */ SIMPLE, UITest::USER_QUIT);
 }
 
-// http://crbug.com/52858
-#if defined(OS_MACOSX)
-#define MAYBE_SimpleSessionEnding FLAKY_SimpleSessionEnding
-#define MAYBE_TwentyTabsWindowClose FLAKY_TwentyTabsWindowClose
-#define MAYBE_TwentyTabsUserQuit FLAKY_TwentyTabsUserQuit
-#else
-#define MAYBE_SimpleSessionEnding SimpleSessionEnding
-#define MAYBE_TwentyTabsWindowClose TwentyTabsWindowClose
-#define MAYBE_TwentyTabsUserQuit TwentyTabsUserQuit
-#endif
-
-TEST_F(ShutdownTest, MAYBE_SimpleSessionEnding) {
+TEST_F(ShutdownTest, SimpleSessionEnding) {
   RunShutdownTest("shutdown", "simple-session-ending",
                   true, /* important */ SIMPLE, UITest::SESSION_ENDING);
 }
 
-TEST_F(ShutdownTest, MAYBE_TwentyTabsWindowClose) {
+TEST_F(ShutdownTest, TwentyTabsWindowClose) {
   RunShutdownTest("shutdown", "twentytabs-window-close",
                   true, /* important */ TWENTY_TABS, UITest::WINDOW_CLOSE);
 }
 
-TEST_F(ShutdownTest, MAYBE_TwentyTabsUserQuit) {
+TEST_F(ShutdownTest, TwentyTabsUserQuit) {
   RunShutdownTest("shutdown", "twentytabs-user-quit",
                   true, /* important */ TWENTY_TABS, UITest::USER_QUIT);
 }