Replace string::find(prefix) == 0 pattern with base::StartsWith().

ppapi/shared_impl/test_utils.cc

Index: ppapi/shared_impl/test_utils.cc
diff --git a/ppapi/shared_impl/test_utils.cc b/ppapi/shared_impl/test_utils.cc
index 2ab8c5a27dccc43f8ee59cd1a14bd2b2d332f038..18bc9e3af325c6eed9e2e42ca4972842a5fb04ad 100644
--- a/ppapi/shared_impl/test_utils.cc
+++ b/ppapi/shared_impl/test_utils.cc
@@ -213,8 +213,11 @@ bool TestEqual(const PP_Var& expected,
 }
 
 std::string StripTestPrefixes(const std::string& test_name) {
-  if (test_name.find("DISABLED_") == 0)
-    return test_name.substr(strlen("DISABLED_"));
+  const char kDisabledPrefix[] = "DISABLED_";
+  if (base::StartsWith(test_name, kDisabledPrefix,
+                       base::CompareCase::SENSITIVE)) {
+    return test_name.substr(sizeof(kDisabledPrefix) - 1);
+  }
   return test_name;
 }