LeakDetector: Terminate all WebEmbeddedWorkerImpl before counting

Source/web/WebLeakDetector.cpp

Index: Source/web/WebLeakDetector.cpp
diff --git a/Source/web/WebLeakDetector.cpp b/Source/web/WebLeakDetector.cpp
index 3cd2d162d7ca933948fef8d5b2e27c0007a82dea..21323e4c42451fe8ba111b0d6d9fb9145aac96bc 100644
--- a/Source/web/WebLeakDetector.cpp
+++ b/Source/web/WebLeakDetector.cpp
@@ -41,6 +41,7 @@
 #include "platform/Timer.h"
 #include "public/web/WebDocument.h"
 #include "public/web/WebLocalFrame.h"
+#include "web/WebEmbeddedWorkerImpl.h"
 
 #include <v8.h>
 
@@ -82,6 +83,7 @@ private:
 
 void WebLeakDetectorImpl::collectGarbageAndGetDOMCounts(WebLocalFrame* frame)
 {
+    WebEmbeddedWorkerImpl::terminateAll();

[michaeln, 2014/07/25 00:07:09]

i think it will take some time to unwind the background threads, do you need a
continuation (completioncallback) of some kind?

[kouhei (in TOK), 2014/07/25 01:33:09]

LeakDetector already flushes the task queue 2 times for oilpan GC, so I think
this is practically fine. Can I try landing as this first?

[michaeln, 2014/07/25 02:49:52]

i doubt if the collection of running instances is empty in two turns of the
message loop, are you able to test prior to landing?

[kouhei (in TOK), 2014/07/25 05:00:39]

Yes I confirmed that there are no false positive leaks after this patch is
applied.

     memoryCache()->evictResources();
 
     {