Allow multiple logging::LogMessage{Handler,Listener}s

chrome/browser/media/webrtc/webrtc_browsertest_base.h

Index: chrome/browser/media/webrtc/webrtc_browsertest_base.h
diff --git a/chrome/browser/media/webrtc/webrtc_browsertest_base.h b/chrome/browser/media/webrtc/webrtc_browsertest_base.h
index e6a0461841a5d9b036b1d10e135ff1b6dc4a9e25..c7a2acfa5fe201f4780389a11877b017e44feb93 100644
--- a/chrome/browser/media/webrtc/webrtc_browsertest_base.h
+++ b/chrome/browser/media/webrtc/webrtc_browsertest_base.h
@@ -21,6 +21,15 @@ namespace content {
 class WebContents;
 }
 
+class JavascriptErrorDetectingListener : logging::LogMessageListener {
+ public:
+  void OnMessage(int severity,
+                 const char* file,
+                 int line,
+                 size_t message_start,
+                 const std::string& str) override;
+};
+
 // Base class for WebRTC browser tests with useful primitives for interacting
 // getUserMedia. We use inheritance here because it makes the test code look
 // as clean as it can be.
@@ -200,6 +209,7 @@ class WebRtcTestBase : public InProcessBrowserTest {
       content::WebContents* tab_contents,
       const std::string& constraints) const;
 
+  JavascriptErrorDetectingListener listener_;
   bool detect_errors_in_javascript_;
 
   DISALLOW_COPY_AND_ASSIGN(WebRtcTestBase);