Refactor Timer classes in preparation for landing FrameTimers.

third_party/WebKit/Source/core/frame/SuspendableTimer.cpp

Index: third_party/WebKit/Source/core/frame/SuspendableTimer.cpp
diff --git a/third_party/WebKit/Source/core/frame/SuspendableTimer.cpp b/third_party/WebKit/Source/core/frame/SuspendableTimer.cpp
index 4f49681c7709d193d4d953659b2cfafcef8f6a68..2df5d0f086bcfb41e64d9502cd78d7ba5d1b3395 100644
--- a/third_party/WebKit/Source/core/frame/SuspendableTimer.cpp
+++ b/third_party/WebKit/Source/core/frame/SuspendableTimer.cpp
@@ -34,7 +34,8 @@ const double kNextFireIntervalInvalid = -1.0;
 }
 
 SuspendableTimer::SuspendableTimer(ExecutionContext* context)
-    : ActiveDOMObject(context)
+    : TimerBase(TimerBase::getDefaultTaskRunner())
+    , ActiveDOMObject(context)
     , m_nextFireInterval(kNextFireIntervalInvalid)
     , m_repeatInterval(0)
 #if ENABLE(ASSERT)