Move base::va_copy from a function to a macro.

base/string_util.cc

Index: base/string_util.cc
diff --git a/base/string_util.cc b/base/string_util.cc
index 2699f26833b835b0d0a90d7ba9c0921c92b7e085..2f20d780e9b3fa48a958e0b7a70eaef8a1283f85 100644
--- a/base/string_util.cc
+++ b/base/string_util.cc
@@ -915,7 +915,7 @@ static void StringAppendVT(StringType* dst,
   typename StringType::value_type stack_buf[1024];
 
   va_list backup_ap;
-  base::va_copy(backup_ap, ap);
+  GG_VA_COPY(backup_ap, ap);
 
 #if !defined(OS_WIN)
   errno = 0;
@@ -962,7 +962,7 @@ static void StringAppendVT(StringType* dst,
     std::vector<typename StringType::value_type> mem_buf(mem_length);
 
     // Restore the va_list before we use it again.
-    base::va_copy(backup_ap, ap);
+    GG_VA_COPY(backup_ap, ap);
 
     result = vsnprintfT(&mem_buf[0], mem_length, format, ap);
     va_end(backup_ap);