[cros] Added histograms for user image usage

chrome/browser/ui/webui/options/chromeos/change_picture_options_handler.cc

Index: chrome/browser/ui/webui/options/chromeos/change_picture_options_handler.cc
diff --git a/chrome/browser/ui/webui/options/chromeos/change_picture_options_handler.cc b/chrome/browser/ui/webui/options/chromeos/change_picture_options_handler.cc
index 0cc1a2b65d860a85a69fbac7f0e699cae6254514..cacae287171dea3860828eff8b70fcb1609d6bcd 100644
--- a/chrome/browser/ui/webui/options/chromeos/change_picture_options_handler.cc
+++ b/chrome/browser/ui/webui/options/chromeos/change_picture_options_handler.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/ui/webui/options/chromeos/change_picture_options_handler.h"
 
 #include "base/callback.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/values.h"
 #include "chrome/browser/chromeos/login/default_user_images.h"
@@ -151,12 +152,18 @@ void ChangePictureOptionsHandler::HandleSelectImage(const ListValue* args) {
   user_manager->SaveUserImagePath(
       user_manager->logged_in_user().email(),
       GetDefaultImagePath(user_image_index));
+  UMA_HISTOGRAM_ENUMERATION("UserImage.ChangeChoice",
+                            user_image_index,
+                            kDefaultImagesCount + 2);

[jar (doing other things), 2011/08/10 17:48:52]

nit suggestion: Since you name and define (the size of) this histogram three
times, it is probably worth factoring it out to a little local static function
that just takes the sample.  Too many folks instigate typos in one of these
definitions, and it is just easier to avoid replicating the macro invocation. 
In addition to readability, it might actually compile a tad smaller (macro
invocation has a few lines of code)... but I'm focusing on readability and
maintainability.

 }
 
 void ChangePictureOptionsHandler::FileSelected(const FilePath& path,
                                                int index,
                                                void* params) {
   UserManager::Get()->LoadLoggedInUserImage(path);
+  UMA_HISTOGRAM_ENUMERATION("UserImage.ChangeChoice",
+                            kDefaultImagesCount + 1,
+                            kDefaultImagesCount + 2);
 }
 
 void ChangePictureOptionsHandler::OnPhotoAccepted(const SkBitmap& photo) {
@@ -168,6 +175,9 @@ void ChangePictureOptionsHandler::OnPhotoAccepted(const SkBitmap& photo) {
 
   user_manager->SetLoggedInUserImage(photo);
   user_manager->SaveUserImage(user.email(), photo);
+  UMA_HISTOGRAM_ENUMERATION("UserImage.ChangeChoice",
+                            kDefaultImagesCount,
+                            kDefaultImagesCount + 2);
 }
 
 gfx::NativeWindow ChangePictureOptionsHandler::GetBrowserWindow() const {