Preparation CL for WebRTC performance test using promise-based getStats

chrome/browser/media/webrtc/webrtc_browsertest_base.cc

Index: chrome/browser/media/webrtc/webrtc_browsertest_base.cc
diff --git a/chrome/browser/media/webrtc/webrtc_browsertest_base.cc b/chrome/browser/media/webrtc/webrtc_browsertest_base.cc
index ec41b87a5229ac0072d721e8985317ff4111099b..57d0d59d1dbfef45b2234adb59ec07fd346bd579 100644
--- a/chrome/browser/media/webrtc/webrtc_browsertest_base.cc
+++ b/chrome/browser/media/webrtc/webrtc_browsertest_base.cc
@@ -494,6 +494,21 @@ std::vector<std::string> WebRtcTestBase::VerifyStatsGeneratedPromise(
   return JsonArrayToVectorOfStrings(result.substr(3));
 }
 
+scoped_refptr<content::RTCStatsReportDictionary>
+WebRtcTestBase::GetStatsReportDictionary(content::WebContents* tab) const {
+  std::string result = ExecuteJavascript("getStatsAsDictionary()", tab);

[hbos_chromium, 2016/11/30 11:30:56]

nit: I'll rename this to getStatsReportDictionary so the .cc and .js layers have
matching names.

+  EXPECT_TRUE(base::StartsWith(result, "ok-", base::CompareCase::SENSITIVE));
+  std::unique_ptr<base::Value> parsed_json = base::JSONReader::Read(
+      result.substr(3));
+  base::DictionaryValue* dictionary;
+  CHECK(parsed_json);
+  CHECK(parsed_json->GetAsDictionary(&dictionary));
+  ignore_result(parsed_json.release());
+  return scoped_refptr<content::RTCStatsReportDictionary>(
+      new content::RTCStatsReportDictionary(
+          std::unique_ptr<base::DictionaryValue>(dictionary)));
+}
+
 std::vector<std::string> WebRtcTestBase::GetWhitelistedStatsTypes(
     content::WebContents* tab) const {
   return JsonArrayToVectorOfStrings(