Do not attempt an Oilpan memory pressure GC if nested.

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 691 matching lines @@
 
 #if PRINT_HEAP_STATS
     dataLogF("ThreadState::scheduleGCIfNeeded\n");
 #endif
 
     // Allocation is allowed during sweeping, but those allocations should not
     // trigger nested GCs.
     if (isGCForbidden())
         return;
 
+    if (isSweepingInProgress())
+        return;
+    ASSERT(!sweepForbidden());
+
     if (shouldForceMemoryPressureGC()) {
         completeSweep();
         if (shouldForceMemoryPressureGC()) {
 #if PRINT_HEAP_STATS
             dataLogF("Scheduled MemoryPressureGC\n");
 #endif
             Heap::collectGarbage(BlinkGC::HeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::MemoryPressureGC);
             return;
         }
     }
 
-    if (isSweepingInProgress())
-        return;
-    ASSERT(!sweepForbidden());
-
     if (shouldForceConservativeGC()) {
         completeSweep();
         if (shouldForceConservativeGC()) {
 #if PRINT_HEAP_STATS
             dataLogF("Scheduled ConservativeGC\n");
 #endif
             Heap::collectGarbage(BlinkGC::HeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::ConservativeGC);
             return;
         }
     }
@@ skipping 746 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