Revert of Change WokerThread to use a blink::WebThread.

Source/platform/scheduler/SchedulerTest.cpp

Index: Source/platform/scheduler/SchedulerTest.cpp
diff --git a/Source/platform/scheduler/SchedulerTest.cpp b/Source/platform/scheduler/SchedulerTest.cpp
index dba68c7a807f306279d8b247632fc0075c613ab8..0b35485e9232fb0518f3c5ef9e964dca34c5de72 100644
--- a/Source/platform/scheduler/SchedulerTest.cpp
+++ b/Source/platform/scheduler/SchedulerTest.cpp
@@ -40,21 +40,6 @@
     }
 
     virtual void exitRunLoop() OVERRIDE
-    {
-        ASSERT_NOT_REACHED();
-    }
-
-    virtual void setSharedTimerFiredFunction(SharedTimerFunction timerFunction) OVERRIDE
-    {
-        ASSERT_NOT_REACHED();
-    }
-
-    virtual void setSharedTimerFireInterval(double interval) OVERRIDE
-    {
-        ASSERT_NOT_REACHED();
-    }
-
-    virtual void stopSharedTimer() OVERRIDE
     {
         ASSERT_NOT_REACHED();
     }