content: Update crash key and discardable memory usage counter in child process.

content/child/child_discardable_shared_memory_manager.h

Index: content/child/child_discardable_shared_memory_manager.h
diff --git a/content/child/child_discardable_shared_memory_manager.h b/content/child/child_discardable_shared_memory_manager.h
index a5b8081fe03ce6f9d103619349304934a9a165fe..de4e7c79ea40c0a1fbba608bb3356e0d1541121e 100644
--- a/content/child/child_discardable_shared_memory_manager.h
+++ b/content/child/child_discardable_shared_memory_manager.h
@@ -36,10 +36,12 @@ class CONTENT_EXPORT ChildDiscardableSharedMemoryManager
  private:
   scoped_ptr<base::DiscardableSharedMemory>
   AllocateLockedDiscardableSharedMemory(size_t size);
+  void BytesAllocatedChanged(size_t new_bytes_allocated) const;
 
   mutable base::Lock lock_;
   DiscardableSharedMemoryHeap heap_;
   scoped_refptr<ThreadSafeSender> sender_;
+  size_t bytes_allocated_;
 
   DISALLOW_COPY_AND_ASSIGN(ChildDiscardableSharedMemoryManager);
 };