Add UMA to study the video types for mobile

content/browser/media/android/browser_media_player_manager.cc

Index: content/browser/media/android/browser_media_player_manager.cc
diff --git a/content/browser/media/android/browser_media_player_manager.cc b/content/browser/media/android/browser_media_player_manager.cc
index c847a275b8f37d484775164dd90079ab69a135e7..925aada156823ad16f643da59d3ca132bc050c18 100644
--- a/content/browser/media/android/browser_media_player_manager.cc
+++ b/content/browser/media/android/browser_media_player_manager.cc
@@ -6,6 +6,7 @@
 
 #include "base/android/scoped_java_ref.h"
 #include "base/command_line.h"
+#include "base/metrics/histogram.h"
 #include "content/browser/android/content_view_core_impl.h"
 #include "content/browser/media/android/browser_demuxer_android.h"
 #include "content/browser/media/android/media_resource_getter_impl.h"
@@ -103,10 +104,18 @@ MediaPlayerAndroid* BrowserMediaPlayerManager::CreateMediaPlayer(
             media_player_params.url)) {
         media_player_bridge->Initialize();
       }
+      std::string path = media_player_params.url.path();
+      if (EndsWith(path, ".m3u8", true) || EndsWith(path, ".m3u", true)) {
+        UMA_HISTOGRAM_BOOLEAN("MobileVideo.IsVideoUrlHLSVideo", true);
+      } else {
+        UMA_HISTOGRAM_BOOLEAN("MobileVideo.IsVideoUrlHLSVideo", false);

[Ilya Sherman, 2014/08/26 19:54:28]

nit: Please write this as

bool is_hls_video = EndsWith(path, ".m3u8", true) || EndsWith(path, ".m3u",
true);
UMA_HISTOGRAM_BOOLEAN("MobileVideo.IsVideoUrlHLSVideo", is_hls_video);

[qinmin, 2014/08/27 00:10:00]

Done.

+      }
+      UMA_HISTOGRAM_BOOLEAN("MobileVideo.IsRegularVideoUrl", true);
       return media_player_bridge;
     }
 
     case MEDIA_PLAYER_TYPE_MEDIA_SOURCE: {
+      UMA_HISTOGRAM_BOOLEAN("MobileVideo.IsRegularVideoUrl", false);

[Ilya Sherman, 2014/08/26 19:54:29]

nit: It's generally best to avoid repeating UMA_HISTOGRAM macros for a single
histogram, to reduce the likelihood of having a typo in just one of the code
paths.  I'd suggest creating a tiny wrapper function to which you pass |true| or
|false| to be emitted to the histogram.

[qinmin, 2014/08/27 00:10:00]

Done.

       return new MediaSourcePlayer(
           media_player_params.player_id,
           manager,