Reinstate memory pressure Oilpan GC check post V8 major 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 4a1efe48e8904b9f5bcf581155bcf3d28980ee82..9222e8bb75494167a15e14433158469e96e62842 100644
--- a/third_party/WebKit/Source/platform/heap/ThreadState.cpp
+++ b/third_party/WebKit/Source/platform/heap/ThreadState.cpp
@@ -670,6 +670,18 @@ bool ThreadState::shouldForceConservativeGC()
     return judgeGCThreshold(32 * 1024 * 1024, 5.0);
 }
 
+bool ThreadState::forceMemoryPressureGCIfNeeded()
+{
+    if (!shouldForceMemoryPressureGC())
+        return false;
+    completeSweep();
+    if (!shouldForceMemoryPressureGC())
+        return false;
+
+    Heap::collectGarbage(HeapPointersOnStack, GCWithoutSweep, Heap::ConservativeGC);
+    return true;
+}
+
 void ThreadState::scheduleV8FollowupGCIfNeeded(V8GCType gcType)
 {
     ASSERT(checkThread());
@@ -678,6 +690,11 @@ void ThreadState::scheduleV8FollowupGCIfNeeded(V8GCType gcType)
     if (isGCForbidden())
         return;
 
+    // If V8 has acted on a memory pressure signal and performed a major GC,
+    // follow up, if needed.
+    if (gcType == V8MajorGC && forceMemoryPressureGCIfNeeded())
+        return;
+
     if (isSweepingInProgress())
         return;
     ASSERT(!sweepForbidden());