Add UMA to track app launcher discoverability.

chrome/browser/ui/app_list/app_list_service.h

Index: chrome/browser/ui/app_list/app_list_service.h
diff --git a/chrome/browser/ui/app_list/app_list_service.h b/chrome/browser/ui/app_list/app_list_service.h
index 7205ad8f4aa5b7b01cfca6a49cf435281b530650..f8cc151f6c550a53c10a7ba900cea23ccaaf1d9b 100644
--- a/chrome/browser/ui/app_list/app_list_service.h
+++ b/chrome/browser/ui/app_list/app_list_service.h
@@ -27,6 +27,20 @@ class ImageSkia;
 
 class AppListService {
  public:
+  // Source that triggers the app launcher being enabled. This is used for UMA
+  // to track discoverability of the app lancher shortcut after install.
+  enum AppListEnableSource {
+    ENABLE_NOT_RECORDED,       // Indicates app launcher not recently enabled.
+    ENABLE_FOR_APP_INSTALL,    // Triggered by a webstore packaged app install.
+    ENABLE_VIA_WEBSTORE_LINK,  // Triggered by webstore explicitly via API.
+    ENABLE_VIA_COMMAND_LINE,   // Triggered by --enable-app-list.
+    ENABLE_ON_REINSTALL,       // Triggered by Chrome reinstall finding pref.
+    ENABLE_ALREADY_ENABLED,    // Enabled a second time. This overrides a prior
+                               // ENABLE_FOR_APP_INSTALL since it will auto-show
+                               // the app launcher.
+    ENABLE_NUM_ENABLE_SOURCES
+  };
+
   // Get the AppListService for the current platform and specified
   // |desktop_type|.
   static AppListService* Get(chrome::HostDesktopType desktop_type);
@@ -62,6 +76,10 @@ class AppListService {
   // profile to local prefs as the default app list profile.
   virtual void ShowForProfile(Profile* requested_profile) = 0;
 
+  // Show the app list due to a trigger which was not an explicit user action
+  // to show the app list. E.g. the auto-show when installing an app. For UMA.

[benwells, 2014/02/09 21:08:07]

Nit: I think I know what the 'for uma' sentence means but it won't brr clear
outside the context of this cl. Maybe remove or expand.

[tapted, 2014/02/10 02:54:29]

Done. (Expanded - I thought it could still be hard for someone to reason about
how to pick between Show or AutoShow without explaining why it existed).

+  virtual void AutoShowForProfile(Profile* requested_profile) = 0;
+
   // Dismiss the app list.
   virtual void DismissAppList() = 0;
 
@@ -73,7 +91,8 @@ class AppListService {
 
   // Enable the app list. What this does specifically will depend on the host
   // operating system and shell.
-  virtual void EnableAppList(Profile* initial_profile) = 0;
+  virtual void EnableAppList(Profile* initial_profile,
+                             AppListEnableSource enable_source) = 0;
 
   // Get the window the app list is in, or NULL if the app list isn't visible.
   virtual gfx::NativeWindow GetAppListWindow() = 0;