rewrite_to_chrome_style: Don't put a trailing _ on static consts.

tools/clang/rewrite_to_chrome_style/tests/constants-expected.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 namespace blink {
 
 // Simple global constants.
 const char kHelloWorldConstant[] = "Hello world!";
 // Make sure a one-character constant doesn't get mangled.
 const float kE = 2.718281828;
 // Some constants start with a capital letter already.
 const int kSpeedOfLightInMetresPerSecond = 299792458;
 
 // Already Chrome style, so shouldn't change.
 const float kPi = 3.141592654;
 
 class C {
  public:
   // Static class constants.
-  static const int kUsefulConstant_ = 8;
+  static const int kUsefulConstant = 8;
   // Note: s_ prefix should not be retained.
-  static const int kStaticConstant_ = 9;
+  static const int kStaticConstant = 9;
   // Note: m_ prefix should not be retained even though the proper prefix is s_.
-  static const int kSuperNumber_ = 42;
+  static const int kSuperNumber = 42;
 
   // Not a constant even though it has static storage duration.
   static const char* current_event_;
 
   static int Function();
 
   static void FunctionWithConstant() {
     const int kFunctionConstant = 4;
     const int kFunctionConstantFromExpression = 4 + 6;
     const int kFunctionConstantFromOtherConsts =
         kFunctionConstant + kFunctionConstantFromExpression;
     const int kShouldBeRenamedToAConst = 9 - 2;
     const int kShouldAlsoBeRenamedToAConst =
         kFunctionConstant + kFunctionConstantFromOtherConsts;
     const int not_compile_time_const = kFunctionConstant + Function();
   }
 };
 
 void F() {
   // Constant in function body.
   static const char kStaticString[] = "abc";
   // Constant-style naming, since it's initialized with a literal.
   const char* const kNonStaticStringConstant = "def";
   // Not constant-style naming, since it's not initialized with a literal.
   const char* const non_static_string_unconstant = kNonStaticStringConstant;
 }
 
 }  // namespace blink