Revert of Use a C++11 feature in a single file, to discover if this works everywhere.

base/compiler_specific.h

Index: base/compiler_specific.h
diff --git a/base/compiler_specific.h b/base/compiler_specific.h
index a93d350aae0999964bf29c30b58469a728aa2ac9..9e2111db6b6e1aea9aa59beb96047c3c3ef2c3eb 100644
--- a/base/compiler_specific.h
+++ b/base/compiler_specific.h
@@ -137,14 +137,30 @@
 // method in the parent class.
 // Use like:
 //   virtual void foo() OVERRIDE;
+#if defined(__clang__) || defined(COMPILER_MSVC)
 #define OVERRIDE override
+#elif defined(COMPILER_GCC) && __cplusplus >= 201103 && \
+      (__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >= 40700
+// GCC 4.7 supports explicit virtual overrides when C++11 support is enabled.
+#define OVERRIDE override
+#else
+#define OVERRIDE
+#endif
 
 // Annotate a virtual method indicating that subclasses must not override it,
 // or annotate a class to indicate that it cannot be subclassed.
 // Use like:
 //   virtual void foo() FINAL;
 //   class B FINAL : public A {};
+#if defined(__clang__) || defined(COMPILER_MSVC)
 #define FINAL final
+#elif defined(COMPILER_GCC) && __cplusplus >= 201103 && \
+      (__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >= 40700
+// GCC 4.7 supports explicit virtual overrides when C++11 support is enabled.
+#define FINAL final
+#else
+#define FINAL
+#endif
 
 // Annotate a function indicating the caller must examine the return value.
 // Use like: