Oilpan: Don't send a BlinkGC.CompleteSweep UMA from non-main threads

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

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1096 matching lines @@
             ScriptForbiddenScope::enter();
 
         TRACE_EVENT0("blink_gc", "ThreadState::completeSweep");
         double startTime = WTF::currentTimeMS();
 
         static_assert(BlinkGC::EagerSweepHeapIndex == 0, "Eagerly swept heaps must be processed first.");
         for (int i = 0; i < BlinkGC::NumberOfHeaps; i++)
             m_heaps[i]->completeSweep();
 
         double timeForCompleteSweep = WTF::currentTimeMS() - startTime;
-        Platform::current()->histogramCustomCounts("BlinkGC.CompleteSweep", timeForCompleteSweep, 0, 10 * 1000, 50);
         accumulateSweepingTime(timeForCompleteSweep);
 
-        if (isMainThread())
+        if (isMainThread()) {
             ScriptForbiddenScope::exit();
+            Platform::current()->histogramCustomCounts("BlinkGC.CompleteSweep", timeForCompleteSweep, 1, 10 * 1000, 50);
+        }
     }
 
     postSweep();
 }
 
 void ThreadState::postSweep()
 {
     ASSERT(checkThread());
     Heap::reportMemoryUsageForTracing();
 
@@ skipping 350 matching lines @@
     threadDump->addScalar("dead_count", "objects", totalDeadCount);
     threadDump->addScalar("live_size", "bytes", totalLiveSize);
     threadDump->addScalar("dead_size", "bytes", totalDeadSize);
 
     WebMemoryAllocatorDump* heapsDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(heapsDumpName);
     WebMemoryAllocatorDump* classesDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(classesDumpName);
     BlinkGCMemoryDumpProvider::instance()->currentProcessMemoryDump()->addOwnershipEdge(classesDump->guid(), heapsDump->guid());
 }
 
 } // namespace blink