No longer clean out main thread's heap for LSan's benefit.

third_party/WebKit/Source/platform/heap/ThreadState.cpp

Index: third_party/WebKit/Source/platform/heap/ThreadState.cpp
diff --git a/third_party/WebKit/Source/platform/heap/ThreadState.cpp b/third_party/WebKit/Source/platform/heap/ThreadState.cpp
index 53497e71765aa20f04d9c4cb0688c20de2592bc1..6ae1096dacf00a01271040cb4cd6b5fd044a5a1e 100644
--- a/third_party/WebKit/Source/platform/heap/ThreadState.cpp
+++ b/third_party/WebKit/Source/platform/heap/ThreadState.cpp
@@ -331,27 +331,8 @@ void ThreadState::runTerminationGC() {
 void ThreadState::cleanupMainThread() {
   ASSERT(isMainThread());
 
-#if defined(LEAK_SANITIZER)
-  // See comment below, clear out most garbage before releasing static
-  // persistents should some of the finalizers depend on touching
-  // these persistents.
-  collectAllGarbage();
-#endif
-
   releaseStaticPersistentNodes();
 
-#if defined(LEAK_SANITIZER)
-  // If LSan is about to perform leak detection, after having released all
-  // the registered static Persistent<> root references to global caches
-  // that Blink keeps, follow up with a round of GCs to clear out all
-  // what they referred to.
-  //
-  // This is not needed for caches over non-Oilpan objects, as they're
-  // not scanned by LSan due to being held in non-global storage
-  // ("static" references inside functions/methods.)
-  collectAllGarbage();
-#endif
-
   // Finish sweeping before shutting down V8. Otherwise, some destructor
   // may access V8 and cause crashes.
   completeSweep();