GM: include filename extension (.png) of each output file in JSON summary

gm/gm_expectations.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef gm_expectations_DEFINED
 #define gm_expectations_DEFINED
 
 #include "gm.h"
@@ skipping 23 matching lines @@
     typedef Json::UInt64 Checksum;
     static inline Json::Value asJsonValue(Checksum checksum) {
         return checksum;
     }
     static inline Checksum asChecksum(Json::Value jsonValue) {
         return jsonValue.asUInt64();
     }
 
     void gm_fprintf(FILE *stream, const char format[], ...);
 
+    /**
+     * Assembles rootPath and relativePath into a single path, like this:
+     * rootPath/relativePath
+     *
+     * Uses SkPATH_SEPARATOR, to work on all platforms.
+     *
+     * TODO(epoger): This should probably move into SkOSFile.h
+     */
+    SkString SkPathJoin(const char *rootPath, const char *relativePath);
+
     SkString make_filename(const char path[],
                            const char renderModeDescriptor[],
                            const char *name,
                            const char suffix[]);
 
     Json::Value ActualResultAsJsonValue(const SkHashDigest& result);
 
     Json::Value CreateJsonTree(Json::Value expectedResults,
                                Json::Value actualResultsFailed,
                                Json::Value actualResultsFailureIgnored,
@@ skipping 157 matching lines @@
          * Returns true if successful.
          */
         static bool Parse(const char *jsonPath, Json::Value *jsonRoot);
 
         Json::Value fJsonRoot;
         Json::Value fJsonExpectedResults;
     };
 
 }
 #endif