Revert of Oilpan: Remove page navigation GCs from the prologues of V8's GCs

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 8e056030a3fe3ccaf429059ca98aef207c4a57a5..9de5549437e8814087cb2df86d36621584ab65f4 100644
--- a/third_party/WebKit/Source/platform/heap/ThreadState.cpp
+++ b/third_party/WebKit/Source/platform/heap/ThreadState.cpp
@@ -625,6 +625,17 @@
     // the major GC requests object grouping.
     if (gcType == BlinkGC::V8MajorGC)
         completeSweep();
+
+    // The fact that the PageNavigation GC is scheduled means that there is
+    // a dead frame. In common cases, a sequence of Oilpan's GC => V8 GC =>
+    // Oilpan's GC is needed to collect the dead frame. So we force the
+    // PageNavigation GC before running the V8 GC.
+    if (gcState() == PageNavigationGCScheduled) {
+#if PRINT_HEAP_STATS
+        dataLogF("Scheduled PageNavigationGC\n");
+#endif
+        Heap::collectGarbage(BlinkGC::HeapPointersOnStack, BlinkGC::GCWithSweep, BlinkGC::PageNavigationGC);
+    }
 }
 
 void ThreadState::schedulePageNavigationGCIfNeeded(float estimatedRemovalRatio)