Convert app_launch_index and page_index from int to StringOrdinal.

chrome/browser/extensions/extension_service.cc

Index: chrome/browser/extensions/extension_service.cc
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index 03336f9a9dcfe0656c8630c6be0c4143a6ec4ee8..a1b22f3767c91234cbca0a6e6b11c1a1c7589704 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -2038,7 +2038,9 @@ void ExtensionService::UpdateActiveExtensionsInCrashReporter() {
 }
 
 void ExtensionService::OnExtensionInstalled(
-    const Extension* extension, bool from_webstore, int page_index) {
+    const Extension* extension,
+    bool from_webstore,
+    const StringOrdinal& page_ordinal) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   // Ensure extension is deleted unless we transfer ownership.
@@ -2095,7 +2097,7 @@ void ExtensionService::OnExtensionInstalled(
       extension,
       initial_enable ? Extension::ENABLED : Extension::DISABLED,
       from_webstore,
-      page_index);
+      page_ordinal);
 
   // Unpacked extensions default to allowing file access, but if that has been
   // overridden, don't reset the value.