[memory-infra] Move periodic timer to dump thread

base/trace_event/memory_dump_scheduler.h

Index: base/trace_event/memory_dump_scheduler.h
diff --git a/base/trace_event/memory_dump_scheduler.h b/base/trace_event/memory_dump_scheduler.h
index ab8441bc20031242e5ac5df07f37eac12f66dc23..18721011f099ca42fd82ecf50d73f8e98f1306f2 100644
--- a/base/trace_event/memory_dump_scheduler.h
+++ b/base/trace_event/memory_dump_scheduler.h
@@ -78,6 +78,8 @@ class BASE_EXPORT MemoryDumpScheduler {
     uint32_t light_dump_period_ms;
     uint32_t heavy_dump_period_ms;
 
+    bool is_enabled_for_testing;
+
     DISALLOW_COPY_AND_ASSIGN(PeriodicTriggerState);
   };
 
@@ -117,8 +119,11 @@ class BASE_EXPORT MemoryDumpScheduler {
   MemoryDumpScheduler();
   ~MemoryDumpScheduler();
 
+  // Helper to enable timer on polling thread.
+  void EnablePeriodicTimerOnPollingThread();
+
   // Helper to set polling disabled.
-  void DisablePollingOnPollingThread();
+  void DisableTriggersOnPollingThread();
 
   // Periodically called by the timer.
   void RequestPeriodicGlobalDump();
@@ -138,14 +143,14 @@ class BASE_EXPORT MemoryDumpScheduler {
   // True if periodic dumping is enabled.
   bool IsPeriodicTimerRunningForTesting();
 
+  // Timer.Start is not called if disabled, for tests without message loop.
+  void DisablePeriodicTimerForTesting(bool disable);
+
   MemoryDumpManager* mdm_;
 
   // Accessed on the thread of the client before enabling and only accessed on
-  // the thread that called "EnablePeriodicTriggersIfNeeded()" after enabling.
+  // the polling thread after enabling:
   std::unique_ptr<PeriodicTriggerState> periodic_state_;
-
-  // Accessed on the thread of the client before enabling and only accessed on
-  // the polling thread after enabling.
   std::unique_ptr<PollingTriggerState> polling_state_;
 
   // Accessed on the thread of the client only.
@@ -154,6 +159,9 @@ class BASE_EXPORT MemoryDumpScheduler {
   // True when the scheduler is setup. Accessed on the thread of client only.
   bool is_setup_;
 
+  // Disables the Timer.Start for periodic triggers.
+  static bool periodic_timer_disabled_for_testing_;
+
   DISALLOW_COPY_AND_ASSIGN(MemoryDumpScheduler);
 };