predictors: Fix duplicate content type detection.

chrome/browser/predictors/resource_prefetch_predictor.h

Index: chrome/browser/predictors/resource_prefetch_predictor.h
diff --git a/chrome/browser/predictors/resource_prefetch_predictor.h b/chrome/browser/predictors/resource_prefetch_predictor.h
index 15768ecf565f81f3dc87005b2053d29eea206b67..eff512b52a609141f9c22043efe7f4722f1df466 100644
--- a/chrome/browser/predictors/resource_prefetch_predictor.h
+++ b/chrome/browser/predictors/resource_prefetch_predictor.h
@@ -91,6 +91,11 @@ class ResourcePrefetchPredictor
     std::string mime_type;
     bool was_cached;
     GURL redirect_url;  // Empty unless request was redirected to a valid url.
+
+    // Initializes a |URLRequestSummary| from a |URLRequest| response.
+    // Returns true for success.
+    static bool SummarizeResponse(const net::URLRequest& request,
+                                  URLRequestSummary* summary);
   };
 
   ResourcePrefetchPredictor(const ResourcePrefetchPredictorConfig& config,