Cleanup: Better constify some strings in base.

base/test/expectations/expectation_unittest.cc

Index: base/test/expectations/expectation_unittest.cc
diff --git a/base/test/expectations/expectation_unittest.cc b/base/test/expectations/expectation_unittest.cc
index 8a7af71a97eb0274eb77734c818bb2b412c539c2..c0f55a1182139dfb9e2de44fc8eede25235e83b5 100644
--- a/base/test/expectations/expectation_unittest.cc
+++ b/base/test/expectations/expectation_unittest.cc
@@ -71,7 +71,7 @@ TEST(TestExpectationsFunctionsTest, PlatformFromString) {
 }
 
 TEST(TestExpectationsFunctionsTest, IsValidPlatform) {
-  const char* kValidPlatforms[] = {
+  const char* const kValidPlatforms[] = {
     "Win",
     "Win-XP",
     "Win-Vista",
@@ -89,7 +89,7 @@ TEST(TestExpectationsFunctionsTest, IsValidPlatform) {
     "Android",
   };
 
-  const char* kInvalidPlatforms[] = {
+  const char* const kInvalidPlatforms[] = {
     "Solaris",
     "Plan9",
   };