[ios] Adds an Initialize() method to OmahaServiceProvider.

ios/public/provider/chrome/browser/omaha/omaha_service_provider.h

Index: ios/public/provider/chrome/browser/omaha/omaha_service_provider.h
diff --git a/ios/public/provider/chrome/browser/omaha/omaha_service_provider.h b/ios/public/provider/chrome/browser/omaha/omaha_service_provider.h
index 7dd2e767efc63e8bd6ec824752c426d1a8c478f3..e37b1898b7b0c2b7d20ccf1af6ddcd37c06acc2c 100644
--- a/ios/public/provider/chrome/browser/omaha/omaha_service_provider.h
+++ b/ios/public/provider/chrome/browser/omaha/omaha_service_provider.h
@@ -19,6 +19,9 @@ class OmahaServiceProvider {
   OmahaServiceProvider();
   virtual ~OmahaServiceProvider();
 
+  // Initializes the provider.  This method will be called on the UI thread.
+  virtual void Initialize();
+
   // Returns the URL to use for update checks.
   virtual GURL GetUpdateServerURL() const;