Add base::RunLoop and update ui_test_utils to use it to reduce flakiness

chrome/test/base/ui_test_utils.cc

Index: chrome/test/base/ui_test_utils.cc
diff --git a/chrome/test/base/ui_test_utils.cc b/chrome/test/base/ui_test_utils.cc
index efb8a8dbdb8844216b7aa01078abcc029d0b446f..7075d45c95feca7d7ebc6023b8454323dbeda0fd 100644
--- a/chrome/test/base/ui_test_utils.cc
+++ b/chrome/test/base/ui_test_utils.cc
@@ -95,6 +95,21 @@ namespace ui_test_utils {
 
 namespace {
 
+// Helper class to Quit the message loop only once. Subsequent calls to Quit
+// are ignored.
+class MessageLoopQuitter {
+ public:
+  MessageLoopQuitter() : did_quit_(false) { }
+  void Quit() {
+    if (did_quit_)
+      return;
+    did_quit_ = true;
+    MessageLoopForUI::current()->QuitAfterPending();
+  }
+ private:
+  bool did_quit_;
+};
+
 class DOMOperationObserver : public content::NotificationObserver,
                              public content::WebContentsObserver {
  public:
@@ -114,12 +129,12 @@ class DOMOperationObserver : public content::NotificationObserver,
     content::Details<DomOperationNotificationDetails> dom_op_details(details);
     response_ = dom_op_details->json;
     did_respond_ = true;
-    MessageLoopForUI::current()->Quit();
+    message_loop_quitter_.Quit();
   }
 
   // Overridden from content::WebContentsObserver:
   virtual void RenderViewGone(base::TerminationStatus status) OVERRIDE {
-    MessageLoopForUI::current()->Quit();
+    message_loop_quitter_.Quit();
   }
 
   bool GetResponse(std::string* response) WARN_UNUSED_RESULT {
@@ -131,6 +146,7 @@ class DOMOperationObserver : public content::NotificationObserver,
   content::NotificationRegistrar registrar_;
   std::string response_;
   bool did_respond_;
+  MessageLoopQuitter message_loop_quitter_;
 
   DISALLOW_COPY_AND_ASSIGN(DOMOperationObserver);
 };
@@ -163,7 +179,7 @@ class FindInPageNotificationObserver : public content::NotificationObserver {
           active_match_ordinal_ = find_details->active_match_ordinal();
         if (find_details->final_update()) {
           number_of_matches_ = find_details->number_of_matches();
-          MessageLoopForUI::current()->Quit();
+          message_loop_quitter_.Quit();
         } else {
           DVLOG(1) << "Ignoring, since we only care about the final message";
         }
@@ -183,6 +199,7 @@ class FindInPageNotificationObserver : public content::NotificationObserver {
   // The id of the current find request, obtained from WebContents. Allows us
   // to monitor when the search completes.
   int current_find_request_id_;
+  MessageLoopQuitter message_loop_quitter_;
 
   DISALLOW_COPY_AND_ASSIGN(FindInPageNotificationObserver);
 };
@@ -262,10 +279,11 @@ bool ExecuteJavaScriptHelper(RenderViewHost* render_view_host,
 }
 
 void RunAllPendingMessageAndSendQuit(content::BrowserThread::ID thread_id) {
-  MessageLoop::current()->PostTask(FROM_HERE, MessageLoop::QuitClosure());
+  MessageLoop::current()->PostTask(FROM_HERE,
+                                   MessageLoop::QuitWhenIdleClosure());
   RunMessageLoop();
   content::BrowserThread::PostTask(thread_id, FROM_HERE,
-                                   MessageLoop::QuitClosure());
+                                   MessageLoop::QuitAfterPendingClosure());
 }
 
 }  // namespace
@@ -293,7 +311,8 @@ void RunMessageLoop() {
 }
 
 void RunAllPendingInMessageLoop() {
-  MessageLoop::current()->PostTask(FROM_HERE, MessageLoop::QuitClosure());
+  MessageLoop::current()->PostTask(FROM_HERE,
+                                   MessageLoop::QuitWhenIdleClosure());
   ui_test_utils::RunMessageLoop();
 }
 
@@ -331,8 +350,7 @@ void WaitForNavigations(NavigationController* controller,
       number_of_navigations);
   observer.WaitForObservation(
       base::Bind(&ui_test_utils::RunMessageLoop),
-      base::Bind(&MessageLoop::Quit,
-                 base::Unretained(MessageLoopForUI::current())));
+      MessageLoop::QuitAfterPendingClosure());
 }
 
 void WaitForNewTab(Browser* browser) {
@@ -391,8 +409,7 @@ void NavigateToURL(browser::NavigateParams* params) {
   browser::Navigate(params);
   observer.WaitForObservation(
       base::Bind(&ui_test_utils::RunMessageLoop),
-      base::Bind(&MessageLoop::Quit,
-                 base::Unretained(MessageLoopForUI::current())));
+      MessageLoop::QuitAfterPendingClosure());
 
 }
 
@@ -465,8 +482,7 @@ static void NavigateToURLWithDispositionBlockUntilNavigationsComplete(
   if (disposition == CURRENT_TAB) {
     same_tab_observer.WaitForObservation(
         base::Bind(&ui_test_utils::RunMessageLoop),
-        base::Bind(&MessageLoop::Quit,
-                   base::Unretained(MessageLoopForUI::current())));
+        MessageLoop::QuitAfterPendingClosure());
     return;
   } else if (web_contents) {
     NavigationController* controller = &web_contents->GetController();
@@ -773,11 +789,13 @@ bool SendKeyPressSync(const Browser* browser,
 
   bool result;
   result = ui_controls::SendKeyPressNotifyWhenDone(
-      window, key, control, shift, alt, command, MessageLoop::QuitClosure());
+      window, key, control, shift, alt, command,
+      MessageLoop::QuitAfterPendingClosure());
 #if defined(OS_WIN)
   if (!result && BringBrowserWindowToFront(browser)) {
     result = ui_controls::SendKeyPressNotifyWhenDone(
-        window, key, control, shift, alt, command, MessageLoop::QuitClosure());
+        window, key, control, shift, alt, command,
+        MessageLoop::QuitAfterPendingClosure());
   }
 #endif
   if (!result) {
@@ -810,8 +828,8 @@ bool SendKeyPressAndWait(const Browser* browser,
 }
 
 bool SendMouseMoveSync(const gfx::Point& location) {
-  if (!ui_controls::SendMouseMoveNotifyWhenDone(location.x(), location.y(),
-                                                MessageLoop::QuitClosure())) {
+  if (!ui_controls::SendMouseMoveNotifyWhenDone(
+          location.x(), location.y(), MessageLoop::QuitAfterPendingClosure())) {
     return false;
   }
   RunMessageLoop();
@@ -820,7 +838,7 @@ bool SendMouseMoveSync(const gfx::Point& location) {
 
 bool SendMouseEventsSync(ui_controls::MouseButton type, int state) {
   if (!ui_controls::SendMouseEventsNotifyWhenDone(
-          type, state, MessageLoop::QuitClosure())) {
+          type, state, MessageLoop::QuitAfterPendingClosure())) {
     return false;
   }
   RunMessageLoop();
@@ -829,8 +847,7 @@ bool SendMouseEventsSync(ui_controls::MouseButton type, int state) {
 
 TimedMessageLoopRunner::TimedMessageLoopRunner()
     : loop_(new MessageLoopForUI()),
-      owned_(true),
-      quit_loop_invoked_(false) {
+      owned_(true) {
 }
 
 TimedMessageLoopRunner::~TimedMessageLoopRunner() {
@@ -839,22 +856,11 @@ TimedMessageLoopRunner::~TimedMessageLoopRunner() {
 }
 
 void TimedMessageLoopRunner::RunFor(int ms) {
-  QuitAfter(ms);
-  quit_loop_invoked_ = false;
-  loop_->Run();
-}
-
-void TimedMessageLoopRunner::Quit() {
-  quit_loop_invoked_ = true;
-  loop_->PostTask(FROM_HERE, MessageLoop::QuitClosure());
-}
-
-void TimedMessageLoopRunner::QuitAfter(int ms) {
-  quit_loop_invoked_ = true;
   loop_->PostDelayedTask(
       FROM_HERE,
-      MessageLoop::QuitClosure(),
+      MessageLoop::QuitAfterPendingClosure(),
       base::TimeDelta::FromMilliseconds(ms));
+  loop_->Run();
 }
 
 TestWebSocketServer::TestWebSocketServer()
@@ -1033,7 +1039,7 @@ void WindowedNotificationObserver::Observe(
   if (!running_)
     return;
 
-  MessageLoopForUI::current()->Quit();
+  MessageLoopForUI::current()->QuitAfterPending();
   running_ = false;
 }
 
@@ -1110,8 +1116,11 @@ void TitleWatcher::Observe(int type,
     return;
   observed_title_ = *it;
   expected_title_observed_ = true;
-  if (quit_loop_on_observation_)
-    MessageLoopForUI::current()->Quit();
+  if (quit_loop_on_observation_) {
+    // Only call Quit once, on first Observe:
+    quit_loop_on_observation_ = false;
+    MessageLoopForUI::current()->QuitAfterPending();
+  }
 }
 
 BrowserAddedObserver::BrowserAddedObserver()
@@ -1146,7 +1155,7 @@ void DOMMessageQueue::Observe(int type,
   message_queue_.push(dom_op_details->json);
   if (waiting_for_message_) {
     waiting_for_message_ = false;
-    MessageLoopForUI::current()->Quit();
+    MessageLoopForUI::current()->QuitAfterPending();
   }
 }
 
@@ -1221,7 +1230,7 @@ class SnapshotTaker {
   void OnSnapshotTaken(const SkBitmap& bitmap) {
     *bitmap_ = bitmap;
     snapshot_taken_ = true;
-    MessageLoop::current()->Quit();
+    MessageLoop::current()->QuitNow();
   }
 
   SkBitmap* bitmap_;
@@ -1254,7 +1263,7 @@ void OverrideGeolocation(double latitude, double longitude) {
   position.accuracy = 0.;
   position.timestamp = base::Time::Now();
   content::OverrideLocationForTesting(position,
-                                      base::Bind(MessageLoop::QuitClosure()));
+                                      MessageLoop::QuitAfterPendingClosure());
   RunMessageLoop();
 }