Split GM json schema out of display_json_results.py, for sharing with other tools

gm/gm_expectations.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm_expectations.h"
 #include "SkBitmapHasher.h"
 #include "SkImageDecoder.h"
 
 #define DEBUGFAIL_SEE_STDERR SkDEBUGFAIL("see stderr for message")
 
 // These constants must be kept in sync with the JSONKEY_ constants in
-// display_json_results.py !
+// gm_json.py !
 const static char kJsonKey_ActualResults[]   = "actual-results";
 const static char kJsonKey_ActualResults_Failed[]        = "failed";
 const static char kJsonKey_ActualResults_FailureIgnored[]= "failure-ignored";
 const static char kJsonKey_ActualResults_NoComparison[]  = "no-comparison";
 const static char kJsonKey_ActualResults_Succeeded[]     = "succeeded";
 
 const static char kJsonKey_ExpectedResults[] = "expected-results";
 const static char kJsonKey_ExpectedResults_AllowedDigests[] = "allowed-digests";
 const static char kJsonKey_ExpectedResults_IgnoreFailure[]  = "ignore-failure";
 
@@ skipping 232 matching lines @@
         Json::Reader reader;
         if (!reader.parse(bytes, bytes+size, *jsonRoot)) {
             gm_fprintf(stderr, "error parsing JSON file %s\n", jsonPath);
             DEBUGFAIL_SEE_STDERR;
             return false;
         }
         return true;
     }
 
 }