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

Similar to https://codereview.chromium.org/385743002 , but in a file
that's also built in host targets. Depends on r#294584.

If your bot can't deal with this, please let me know!

BUG=none

Committed: https://crrev.com/5928c2f978a43488a2f45fe7da1d91dfdba1d593
Cr-Commit-Position: refs/heads/master@{#294687}

R=ajwong@chromium.org

Review URL: https://codereview.chromium.org/443483002

Cr-Commit-Position: refs/heads/master@{#294961}

base/compiler_specific.h

@@ -137,30 +137,14 @@
 // 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: