Add a noise indicator to the speech bubble volume indicator.

content/browser/speech/speech_input_manager.h

Index: content/browser/speech/speech_input_manager.h
diff --git a/content/browser/speech/speech_input_manager.h b/content/browser/speech/speech_input_manager.h
index a6ba61f0f2a2d4a702313e918f952114dc052940..9415910e712d3775d1699f2e1707e77349138ee1 100644
--- a/content/browser/speech/speech_input_manager.h
+++ b/content/browser/speech/speech_input_manager.h
@@ -35,6 +35,10 @@ class SpeechInputManager {
   // information and command line flags.
   static bool IsFeatureEnabled();
 
+  // Invokes the platform provided microphone settings UI in a non-blocking way,
+  // via the BrowserThread::PROCESS_LAUNCHER thread.
+  static void ShowAudioInputSettings();
+
   // Factory method to access the singleton. We have this method here instead of
   // using Singleton directly in the calling code to aid tests in injection
   // mocks.