[ios] Adds the LogoVendor protocol.

ios/public/provider/chrome/browser/chrome_browser_provider.h

Index: ios/public/provider/chrome/browser/chrome_browser_provider.h
diff --git a/ios/public/provider/chrome/browser/chrome_browser_provider.h b/ios/public/provider/chrome/browser/chrome_browser_provider.h
index d9339224736469605fa1b57955fa7f4185b81542..45191f7e6e3a2686d04722fa1f80443df4e0a58e 100644
--- a/ios/public/provider/chrome/browser/chrome_browser_provider.h
+++ b/ios/public/provider/chrome/browser/chrome_browser_provider.h
@@ -47,9 +47,11 @@ class PrefRegistrySyncable;
 
 @protocol AppRatingPrompt;
 @protocol InfoBarViewProtocol;
+@protocol LogoVendor;
 @protocol TextFieldStyling;
 @class UITextField;
 @class UIView;
+@protocol UrlLoader;
 typedef UIView<InfoBarViewProtocol>* InfoBarViewPlaceholder;
 
 namespace ios {
@@ -151,6 +153,12 @@ class ChromeBrowserProvider {
   // Returns an instance of the voice search provider, if one exists.
   virtual VoiceSearchProvider* GetVoiceSearchProvider() const;
 
+  // Creates and returns an object that can fetch and vend search engine logos.
+  // The caller assumes ownership of the returned object.
+  virtual id<LogoVendor> CreateLogoVendor(
+      ios::ChromeBrowserState* browser_state,
+      id<UrlLoader> loader) const NS_RETURNS_RETAINED;
+
   // Returns the SyncedWindowDelegatesGetter implementation.
   virtual std::unique_ptr<sync_sessions::SyncedWindowDelegatesGetter>
   CreateSyncedWindowDelegatesGetter(ios::ChromeBrowserState* browser_state);