Iterate CRT heap instead of process heap.

BUG=671459,671653

Review-Url: https://codereview.chromium.org/2569753002
Cr-Commit-Position: refs/heads/master@{#437930}

content/renderer/render_thread_impl.cc

@@ -1811,20 +1811,20 @@ void RenderThreadImpl::OnProcessPurgeAndSuspend() {
 namespace {
 
 static size_t GetMallocUsage() {
-  // Only checks the default process heap.
-  HANDLE heap = ::GetProcessHeap();
-  if (heap == NULL)
+  // Iterate through whichever heap the CRT is using.
+  HANDLE crt_heap = reinterpret_cast<HANDLE>(_get_heap_handle());
+  if (crt_heap == NULL)
     return 0;
-  if (!::HeapLock(heap))
+  if (!::HeapLock(crt_heap))
     return 0 ;
   size_t malloc_usage = 0;
   PROCESS_HEAP_ENTRY heap_entry;
   heap_entry.lpData = NULL;
-  while (::HeapWalk(heap, &heap_entry) != 0) {
+  while (::HeapWalk(crt_heap, &heap_entry) != 0) {
     if ((heap_entry.wFlags & PROCESS_HEAP_ENTRY_BUSY) != 0)
       malloc_usage += heap_entry.cbData;
   }
-  ::HeapUnlock(heap);
+  ::HeapUnlock(crt_heap);
   return malloc_usage;
 }