1. Enable large object pointer offset check in release build.

base/allocator/allocator_shim.h

Index: base/allocator/allocator_shim.h
===================================================================
--- base/allocator/allocator_shim.h	(revision 137587)
+++ base/allocator/allocator_shim.h	(working copy)
@@ -14,6 +14,11 @@
 // then a default value (typically set to TCMALLOC).
 void SetupSubprocessAllocator();
 
+// Expose some of tcmalloc functions for test.
+void* TCMallocDoMallocForTest(size_t size);
+void TCMallocDoFreeForTest(void* ptr);
+size_t ExcludeSpaceForMarkForTest(size_t size);
+
 }  // namespace allocator.
 }  // namespace base.