Add UMA logging of extension creation flags.

chrome/browser/extensions/installed_loader.cc

Index: chrome/browser/extensions/installed_loader.cc
diff --git a/chrome/browser/extensions/installed_loader.cc b/chrome/browser/extensions/installed_loader.cc
index dbf79252ff3f693ed80c474858f943bf901db11c..2586c64193d9431c9b663fac273801b8afc62da1 100644
--- a/chrome/browser/extensions/installed_loader.cc
+++ b/chrome/browser/extensions/installed_loader.cc
@@ -114,6 +114,23 @@ BackgroundPageType GetBackgroundPageType(const Extension* extension) {
   return EVENT_PAGE;
 }
 
+// Records the creation flags of an extension grouped by
+// Extension::InitFromValueFlags.
+void RecordCreationFlags(const Extension* extension) {
+  int highest_flag_bit = 0;
+  for (int i = 1; i < Extension::LAST_INIT_FROM_VALUE_FLAGS; i <<= 1)

[benwells, 2014/04/22 06:41:44]

Nit: add a comment explaining what you're doing here / why you're doing this
loop.

[calamity, 2014/04/22 06:56:28]

Done.

+    ++highest_flag_bit;
+
+  int flag = 1;
+  for (int i = 1; i <= highest_flag_bit; ++i) {
+    if (extension->creation_flags() & flag) {
+      UMA_HISTOGRAM_ENUMERATION(
+          "Extensions.LoadCreationFlags", i, highest_flag_bit + 1);
+    }
+    flag <<= 1;
+  }
+}
+
 }  // namespace
 
 InstalledLoader::InstalledLoader(ExtensionService* extension_service)
@@ -403,6 +420,8 @@ void InstalledLoader::LoadAllExtensions() {
     if (extensions::ManagedModeInfo::IsContentPack(ex->get()))
       ++content_pack_count;
 
+    RecordCreationFlags(*ex);
+
     extension_service_->RecordPermissionMessagesHistogram(
         ex->get(), "Extensions.Permissions_Load");
   }