Add UMA for app info dialog

chrome/browser/ui/app_list/app_context_menu.cc

Index: chrome/browser/ui/app_list/app_context_menu.cc
diff --git a/chrome/browser/ui/app_list/app_context_menu.cc b/chrome/browser/ui/app_list/app_context_menu.cc
index ede059983368c9c7f1309452811a2a630420b589..a5f0b719980ddc137ca0de8c4ad2c3f4c9b6bac1 100644
--- a/chrome/browser/ui/app_list/app_context_menu.cc
+++ b/chrome/browser/ui/app_list/app_context_menu.cc
@@ -6,12 +6,14 @@
 
 #include "base/bind.h"
 #include "base/command_line.h"
+#include "base/metrics/histogram.h"
 #include "chrome/browser/extensions/context_menu_matcher.h"
 #include "chrome/browser/extensions/menu_manager.h"
 #include "chrome/browser/prefs/incognito_mode_prefs.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/app_list/app_context_menu_delegate.h"
 #include "chrome/browser/ui/app_list/app_list_controller_delegate.h"
+#include "chrome/browser/ui/apps/app_info_dialog.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/manifest_url_handler.h"
 #include "content/public/common/context_menu_params.h"
@@ -254,6 +256,9 @@ void AppContextMenu::ExecuteCommand(int command_id, int event_flags) {
   } else if (command_id == CREATE_SHORTCUTS) {
     controller_->DoCreateShortcutsFlow(profile_, app_id_);
   } else if (command_id == SHOW_APP_INFO) {
+    UMA_HISTOGRAM_ENUMERATION("Apps.AppInfoDialogLaunched",
+                              AppInfoDialogLaunchSource::FROM_APP_LIST,
+                              AppInfoDialogLaunchSource::NUM_LAUNCH_SOURCES);

[Alexei Svitkine (slow), 2014/08/06 16:46:44]

Since you only have one launch source, is this even needed? Since you're already
adding histograms that get recorded for each time the function below is called.
You can just use the Total Count displayed in the dashboard for those histograms
to get the same info. I am okay with adding such a histogram once there's more
than one launch sources, but with the current code, I don't think it's necessary
since the other histograms should provide enough info.

[sashab, 2014/08/11 01:32:06]

Ahh yup; agreed :) Done.

     controller_->DoShowAppInfoFlow(profile_, app_id_);
   } else if (command_id >= USE_LAUNCH_TYPE_COMMAND_START &&
              command_id < USE_LAUNCH_TYPE_COMMAND_END) {