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

base/message_loop.cc

Index: base/message_loop.cc
diff --git a/base/message_loop.cc b/base/message_loop.cc
index a207659a4a922203a2e3850bbcdde4b1425dd21d..40dabb25e1ca2331cf3e25b39aa28088f6b0f8ca 100644
--- a/base/message_loop.cc
+++ b/base/message_loop.cc
@@ -135,7 +135,8 @@ MessageLoop::MessageLoop(Type type)
 #ifdef OS_WIN
       os_modal_loop_(false),
 #endif  // OS_WIN
-      next_sequence_num_(0) {
+      next_sequence_num_(0),
+      current_run_state_id_(0) {
   DCHECK(!current()) << "should only have one message loop per thread";
   lazy_tls_ptr.Pointer()->Set(this);
 
@@ -313,7 +314,7 @@ void MessageLoop::RunAllPending() {
   RunHandler();
 }
 
-void MessageLoop::Quit() {
+void MessageLoop::QuitWhenIdle() {
   DCHECK_EQ(this, current());
   if (state_) {
     state_->quit_received = true;
@@ -331,13 +332,49 @@ void MessageLoop::QuitNow() {
   }
 }
 
-static void QuitCurrent() {
-  MessageLoop::current()->Quit();
+void MessageLoop::QuitNowByID(int run_id) {
+  DCHECK_EQ(this, current());
+  if (!state_)
+    return;
+  if (state_->run_state_id == run_id)
+    QuitNow();
+
+  // Search back through RunStates for run_id.
+  RunState* run_state = state_;
+  while (run_state) {
+    if (run_state->run_state_id == run_id) {
+      run_state->quit_now_received = true;
+      break;
+    }
+    run_state = run_state->previous_state;
+  }
+}
+
+static void QuitWhenIdleCurrent() {
+  MessageLoop::current()->QuitWhenIdle();
+}
+
+static void QuitNowCurrent() {
+  MessageLoop::current()->QuitNow();
+}
+
+static void QuitNowByIDCurrent(int run_id) {

[jar (doing other things), 2012/06/14 04:50:29]

nit: I think the word "current" is in the wrong place, as it seems to be linked
to "IdCurrent".  Perhaps better is:

QuitCurrentNowByID

<sigh> all names are hard to read... but that might be an improvement.  WDYT?

[jbates, 2012/06/15 02:20:38]

Done.

+  MessageLoop::current()->QuitNowByID(run_id);
+}
+
+// static
+base::Closure MessageLoop::QuitWhenIdleClosure() {
+  return base::Bind(&QuitWhenIdleCurrent);
 }
 
 // static
-base::Closure MessageLoop::QuitClosure() {
-  return base::Bind(&QuitCurrent);
+base::Closure MessageLoop::QuitNowClosure() {
+  return base::Bind(&QuitNowCurrent);
+}
+
+// static
+base::Closure MessageLoop::QuitNowByIDClosure(int run_id) {
+  return base::Bind(&QuitNowByIDCurrent, run_id);
 }
 
 void MessageLoop::SetNestableTasksAllowed(bool allowed) {
@@ -720,23 +757,28 @@ void MessageLoop::ReleaseSoonInternal(
 
 MessageLoop::AutoRunState::AutoRunState(MessageLoop* loop) : loop_(loop) {
   // Make the loop reference us.
-  previous_state_ = loop_->state_;
-  if (previous_state_) {
-    run_depth = previous_state_->run_depth + 1;
+  previous_state = loop_->state_;
+  if (previous_state) {
+    run_depth = previous_state->run_depth + 1;
   } else {
     run_depth = 1;
   }
   loop_->state_ = this;
 
+  run_state_id = ++loop_->current_run_state_id_;
+
   // Initialize the other fields:
   quit_received = false;
+  quit_now_received = false;
 #if !defined(OS_MACOSX) && !defined(OS_ANDROID)
   dispatcher = NULL;
 #endif
 }
 
 MessageLoop::AutoRunState::~AutoRunState() {
-  loop_->state_ = previous_state_;
+  loop_->state_ = previous_state;
+  if (previous_state && previous_state->quit_now_received)
+    MessageLoop::current()->QuitNow();
 }
 
 //------------------------------------------------------------------------------