Revert 255322 "ThreadWatcher: fixes Start/StopWatchingAll."

> ThreadWatcher: fixes Start/StopWatchingAll.
> 
> Start is deferred in relation to Stop, and when they're both called
> within the Start interval, the end result was started.
> 
> BUG=347887
> TEST=unit_tests --gtest_filter=ThreadWatcherList*
> 
> Review URL: https://codereview.chromium.org/183063007

BUG=347887,349987
TBR=bulach@chromium.org

Review URL: https://codereview.chromium.org/188643006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255401 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 0 insertions, 82 deletions

diff --git a/chrome/browser/metrics/thread_watcher.cc b/chrome/browser/metrics/thread_watcher.cc
index 8246b3e..1737593 100644
--- a/chrome/browser/metrics/thread_watcher.cc
+++ b/chrome/browser/metrics/thread_watcher.cc
@@ -409,8 +409,6 @@ bool ThreadWatcher::IsVeryUnresponsive() {
 // static
 ThreadWatcherList* ThreadWatcherList::g_thread_watcher_list_ = NULL;
 // static
-bool ThreadWatcherList::g_stopped_ = false;
-// static
 const int ThreadWatcherList::kSleepSeconds = 1;
 // static
 const int ThreadWatcherList::kUnresponsiveSeconds = 2;
@@ -445,10 +443,6 @@ void ThreadWatcherList::StartWatchingAll(const CommandLine& command_line) {
   ThreadWatcherObserver::SetupNotifications(
       base::TimeDelta::FromSeconds(kSleepSeconds * unresponsive_threshold));
 
-  WatchDogThread::PostTask(
-      FROM_HERE,
-      base::Bind(&ThreadWatcherList::SetStopped, false));
-
   WatchDogThread::PostDelayedTask(
       FROM_HERE,
       base::Bind(&ThreadWatcherList::InitializeAndStartWatching,
@@ -641,12 +635,6 @@ void ThreadWatcherList::InitializeAndStartWatching(
     const CrashOnHangThreadMap& crash_on_hang_threads) {
   DCHECK(WatchDogThread::CurrentlyOnWatchDogThread());
 
-  // This method is deferred in relationship to its StopWatchingAll()
-  // counterpart. If a previous initialization has already happened, or if
-  // stop has been called, there's nothing left to do here.
-  if (g_thread_watcher_list_ || g_stopped_)
-    return;
-
   ThreadWatcherList* thread_watcher_list = new ThreadWatcherList();
   CHECK(thread_watcher_list);
 
@@ -712,9 +700,6 @@ void ThreadWatcherList::DeleteAll() {
   }
 
   DCHECK(WatchDogThread::CurrentlyOnWatchDogThread());
-
-  SetStopped(true);
-
   if (!g_thread_watcher_list_)
     return;
 
@@ -740,12 +725,6 @@ ThreadWatcher* ThreadWatcherList::Find(const BrowserThread::ID& thread_id) {
   return it->second;
 }
 
-// static
-void ThreadWatcherList::SetStopped(bool stopped) {
-  DCHECK(WatchDogThread::CurrentlyOnWatchDogThread());
-  g_stopped_ = stopped;
-}
-
 // ThreadWatcherObserver methods and members.
 //
 // static
diff --git a/chrome/browser/metrics/thread_watcher.h b/chrome/browser/metrics/thread_watcher.h
index 939375a..2c4b027 100644
--- a/chrome/browser/metrics/thread_watcher.h
+++ b/chrome/browser/metrics/thread_watcher.h
@@ -410,7 +410,6 @@ class ThreadWatcherList {
   FRIEND_TEST_ALL_PREFIXES(ThreadWatcherTest, ThreadNamesOnlyArgs);
   FRIEND_TEST_ALL_PREFIXES(ThreadWatcherTest, ThreadNamesAndLiveThresholdArgs);
   FRIEND_TEST_ALL_PREFIXES(ThreadWatcherTest, CrashOnHangThreadsAllArgs);
-  FRIEND_TEST_ALL_PREFIXES(ThreadWatcherListTest, Restart);
   FRIEND_TEST_ALL_PREFIXES(ThreadWatcherAndroidTest,
                            ApplicationStatusNotification);
 
@@ -465,19 +464,10 @@ class ThreadWatcherList {
   // already registered, or to retrieve a pointer to it from the global map.
   static ThreadWatcher* Find(const content::BrowserThread::ID& thread_id);
 
-  // Sets |g_stopped_| on the WatchDogThread. This is necessary to reflect the
-  // state between the delayed |StartWatchingAll| and the immediate
-  // |StopWatchingAll|.
-  static void SetStopped(bool stopped);
-
   // The singleton of this class and is used to keep track of information about
   // threads that are being watched.
   static ThreadWatcherList* g_thread_watcher_list_;
 
-  // StartWatchingAll() is delayed in relation to StopWatchingAll(), so if
-  // a Stop comes first, prevent further initialization.
-  static bool g_stopped_;
-
   // This is the wait time between ping messages.
   static const int kSleepSeconds;
 
diff --git a/chrome/browser/metrics/thread_watcher_unittest.cc b/chrome/browser/metrics/thread_watcher_unittest.cc
index 7efb041..4b799e9 100644
--- a/chrome/browser/metrics/thread_watcher_unittest.cc
+++ b/chrome/browser/metrics/thread_watcher_unittest.cc
@@ -10,7 +10,6 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/message_loop/message_loop_proxy.h"
-#include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_tokenizer.h"
@@ -630,53 +629,3 @@ TEST_F(ThreadWatcherTest, MultipleThreadsNotResponding) {
   // Wait for the io_watcher_'s VeryLongMethod to finish.
   io_watcher_->WaitForWaitStateChange(kUnresponsiveTime * 10, ALL_DONE);
 }
-
-TEST(ThreadWatcherListTest, Restart) {
-  ThreadWatcherList::g_initialize_delay_seconds = 1;
-
-  base::MessageLoopForUI message_loop_for_ui;
-  content::TestBrowserThread ui_thread(BrowserThread::UI, &message_loop_for_ui);
-
-  scoped_ptr<WatchDogThread> watchdog_thread_(new WatchDogThread());
-  watchdog_thread_->Start();
-
-  EXPECT_FALSE(ThreadWatcherList::g_thread_watcher_list_);
-
-  // See http://crbug.com/347887.
-  // StartWatchingAll() will PostDelayedTask to create g_thread_watcher_list_,
-  // whilst StopWatchingAll() will just PostTask to destroy it.
-  // Ensure that when Stop is called, Start will NOT create
-  // g_thread_watcher_list_ later on.
-  ThreadWatcherList::StartWatchingAll(*CommandLine::ForCurrentProcess());
-  ThreadWatcherList::StopWatchingAll();
-  message_loop_for_ui.PostDelayedTask(
-      FROM_HERE,
-      message_loop_for_ui.QuitClosure(),
-      base::TimeDelta::FromSeconds(
-          ThreadWatcherList::g_initialize_delay_seconds));
-  message_loop_for_ui.Run();
-  EXPECT_FALSE(ThreadWatcherList::g_thread_watcher_list_);
-  EXPECT_TRUE(ThreadWatcherList::g_stopped_);
-
-  // Proceed with just |StartWatchingAll| and ensure it'll be started.
-  ThreadWatcherList::StartWatchingAll(*CommandLine::ForCurrentProcess());
-  message_loop_for_ui.PostDelayedTask(
-      FROM_HERE,
-      message_loop_for_ui.QuitClosure(),
-      base::TimeDelta::FromSeconds(
-          ThreadWatcherList::g_initialize_delay_seconds + 1));
-  message_loop_for_ui.Run();
-  EXPECT_TRUE(ThreadWatcherList::g_thread_watcher_list_);
-  EXPECT_FALSE(ThreadWatcherList::g_stopped_);
-
-  // Finally, StopWatchingAll() must stop.
-  ThreadWatcherList::StopWatchingAll();
-  message_loop_for_ui.PostDelayedTask(
-      FROM_HERE,
-      message_loop_for_ui.QuitClosure(),
-      base::TimeDelta::FromSeconds(
-          ThreadWatcherList::g_initialize_delay_seconds));
-  message_loop_for_ui.Run();
-  EXPECT_FALSE(ThreadWatcherList::g_thread_watcher_list_);
-  EXPECT_TRUE(ThreadWatcherList::g_stopped_);
-}