Revert of Oilpan: Implement a GC to take a heap snapshot

Source/platform/heap/ThreadState.cpp

Index: Source/platform/heap/ThreadState.cpp
diff --git a/Source/platform/heap/ThreadState.cpp b/Source/platform/heap/ThreadState.cpp
index b478a51002e467856f2553c6408948ab67046969..eefce3ea7d2444e3dda43b92cd739fc64e8c8d56 100644
--- a/Source/platform/heap/ThreadState.cpp
+++ b/Source/platform/heap/ThreadState.cpp
@@ -838,19 +838,19 @@
     }
 }
 
-void ThreadState::makeConsistentForSweeping(GCType gcType)
+void ThreadState::makeConsistentForSweeping()
 {
     ASSERT(isInGC());
     TRACE_EVENT0("blink_gc", "ThreadState::makeConsistentForSweeping");
     for (int i = 0; i < NumberOfHeaps; ++i)
-        m_heaps[i]->makeConsistentForSweeping(gcType);
-}
-
-void ThreadState::preGC(GCType gcType)
+        m_heaps[i]->makeConsistentForSweeping();
+}
+
+void ThreadState::preGC()
 {
     ASSERT(!isInGC());
     setGCState(GCRunning);
-    makeConsistentForSweeping(gcType);
+    makeConsistentForSweeping();
     prepareRegionTree();
     flushHeapDoesNotContainCacheIfNeeded();
     clearHeapAges();
@@ -878,21 +878,9 @@
     }
 #endif
 
+    setGCState(gcType == GCWithSweep ? EagerSweepScheduled : LazySweepScheduled);
     for (int i = 0; i < NumberOfHeaps; i++)
         m_heaps[i]->prepareForSweep();
-
-    if (gcType == GCWithSweep) {
-        setGCState(EagerSweepScheduled);
-    } else if (gcType == GCWithoutSweep) {
-        setGCState(LazySweepScheduled);
-    } else {
-        takeSnapshot();
-        // This unmarks all marked objects and marks all unmarked objects dead.
-        makeConsistentForSweeping(gcType);
-        // Force setting NoGCScheduled to circumvent checkThread()
-        // in setGCState().
-        m_gcState = NoGCScheduled;
-    }
 }
 
 void ThreadState::preSweep()
@@ -1277,12 +1265,6 @@
     m_likelyToBePromptlyFreed[entryIndex] += 3;
 }
 
-void ThreadState::takeSnapshot()
-{
-    ASSERT(isInGC());
-    // TODO(ssid): Implement this.
-}
-
 #if ENABLE(GC_PROFILING)
 const GCInfo* ThreadState::findGCInfoFromAllThreads(Address address)
 {