Added incident report for variations seed signature mismatch.

chrome/browser/metrics/variations/variations_service.h

Index: chrome/browser/metrics/variations/variations_service.h
diff --git a/chrome/browser/metrics/variations/variations_service.h b/chrome/browser/metrics/variations/variations_service.h
index 108d621dbde88993ef1fd273fd7d5a3b7d5c0ce5..685767d132fe5c99717beafcc849e65557bb01ee 100644
--- a/chrome/browser/metrics/variations/variations_service.h
+++ b/chrome/browser/metrics/variations/variations_service.h
@@ -133,6 +133,12 @@ class VariationsService
     policy_pref_service_ = service;
   }
 
+  // Returns true if the variations seed signature is invalid, in which case
+  // it also sets invalid_signature to that value.
+  bool IsVariationsSeedSignatureInvalid(std::string* invalid_signature) const {

[Alexei Svitkine (slow), 2014/10/14 17:30:01]

This should be implemented in the .cc file, since it's not a trivial method
(else it should use hacker_style).

[Georges Khalil, 2014/10/14 18:00:32]

Done.

+    return seed_store_.GetInvalidSignature(invalid_signature);
+  }
+
  protected:
   // Starts the fetching process once, where |OnURLFetchComplete| is called with
   // the response.