Completely clear the heap ages array.

R=haraken
BUG=468166

Review URL: https://codereview.chromium.org/1021393004

git-svn-id: svn://svn.chromium.org/blink/trunk@192306 bbb929c8-8fbe-4397-9dbb-9b2b20218538
diff --git a/Source/platform/heap/ThreadState.cpp b/Source/platform/heap/ThreadState.cpp
index dd68247..916336b 100644
--- a/Source/platform/heap/ThreadState.cpp
+++ b/Source/platform/heap/ThreadState.cpp
@@ -1106,7 +1106,7 @@
 
 void ThreadState::clearHeapAges()
 {
-    memset(m_heapAges, 0, sizeof(int) * NumberOfHeaps);
+    memset(m_heapAges, 0, sizeof(size_t) * NumberOfHeaps);
     memset(m_likelyToBePromptlyFreed.get(), 0, sizeof(int) * likelyToBePromptlyFreedArraySize);
     m_currentHeapAges = 0;
 }