base: Remove gcc and msvs workaround limitations for arraysize template magic.

base/macros.h

Index: base/macros.h
diff --git a/base/macros.h b/base/macros.h
index 3ea576cc055f97c349dbbf3cad150180edb1eac6..d9043281cf5aba6b6c6ac6b3ca5e449048aa1aa7 100644
--- a/base/macros.h
+++ b/base/macros.h
@@ -52,18 +52,8 @@
 // This template function declaration is used in defining arraysize.
 // Note that the function doesn't need an implementation, as we only
 // use its type.
-template <typename T, size_t N>
-char (&ArraySizeHelper(T (&array)[N]))[N];
-
-// That gcc wants both of these prototypes seems mysterious. VC, for
-// its part, can't decide which to use (another mystery). Matching of
-// template overloads: the final frontier.
-#ifndef _MSC_VER
-template <typename T, size_t N>
-char (&ArraySizeHelper(const T (&array)[N]))[N];
-#endif
-
-#define arraysize(array) (sizeof(::ArraySizeHelper(array)))
+template <typename T, size_t N> char (&ArraySizeHelper(T (&array)[N]))[N];
+#define arraysize(array) (sizeof(ArraySizeHelper(array)))
 
 
 // Use implicit_cast as a safe version of static_cast or const_cast