Update instrumentation for many different bugs based on new UMA data.

content/browser/renderer_host/media/media_stream_manager.cc

Index: content/browser/renderer_host/media/media_stream_manager.cc
diff --git a/content/browser/renderer_host/media/media_stream_manager.cc b/content/browser/renderer_host/media/media_stream_manager.cc
index 06f06b6f2688634b2f36ecb1ced2d7d7df390a47..ff75090776ab39f8fe9acc6659a54820a0fe2093 100644
--- a/content/browser/renderer_host/media/media_stream_manager.cc
+++ b/content/browser/renderer_host/media/media_stream_manager.cc
@@ -1634,15 +1634,15 @@ void MediaStreamManager::InitializeDeviceManagersOnIOThread() {
   // Use an STA Video Capture Thread to try to avoid crashes on enumeration of
   // buggy third party Direct Show modules, http://crbug.com/428958.
   video_capture_thread_.init_com_with_mta(false);
-  // TODO(pkasting): Remove ScopedTracker below once crbug.com/457525 is fixed.
-  tracked_objects::ScopedTracker tracking_profile1(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION(
-          "457525 MediaStreamManager::InitializeDeviceManagersOnIOThread1"));
-  CHECK(video_capture_thread_.Start());
-  // TODO(pkasting): Remove ScopedTracker below once crbug.com/457525 is fixed.
-  tracked_objects::ScopedTracker tracking_profile2(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION(
-          "457525 MediaStreamManager::InitializeDeviceManagersOnIOThread2"));
+  {
+    // TODO(pkasting): Remove ScopedTracker below once crbug.com/457525 is
+    // fixed.
+    tracked_objects::ScopedTracker tracking_profile(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(
+            "457525 "
+            "MediaStreamManager::InitializeDeviceManagersOnIOThread -> Start"));
+    CHECK(video_capture_thread_.Start());
+  }
   video_capture_manager_->Register(this,
                                    video_capture_thread_.message_loop_proxy());
 #else