Merge tcmalloc r111 (perftools v. 1.8) with the chromium/ branch.

third_party/tcmalloc/chromium/src/libc_override.h

Index: third_party/tcmalloc/chromium/src/libc_override.h
===================================================================
--- third_party/tcmalloc/chromium/src/libc_override.h	(revision 93000)
+++ third_party/tcmalloc/chromium/src/libc_override.h	(working copy)
@@ -69,7 +69,15 @@
 static void ReplaceSystemAlloc() { PatchWindowsFunctions(); }
 
 #elif defined(_WIN32) && !defined(WIN32_DO_PATCHING)
+// On Windows we define the allocation functions in
+// base/allocator/allocator_shim.cc, so we can't include
+// libc_override_redefine.h here.
+// We also need to define ReplaceSystemAlloc() somewhere.
+#if 0
 #include "libc_override_redefine.h"
+#else
+static void ReplaceSystemAlloc() { }
+#endif
 
 #elif defined(__APPLE__)
 #include "libc_override_osx.h"