Removed XCallbackParameters and related code.

ios/chrome/browser/app_startup_parameters.h

Index: ios/chrome/browser/app_startup_parameters.h
diff --git a/ios/chrome/browser/app_startup_parameters.h b/ios/chrome/browser/app_startup_parameters.h
index 2d99fe52fc7e3c40acef076db1e69958e63b119f..c732c7c45fe5ef05cae2bbb71664fff19e415648 100644
--- a/ios/chrome/browser/app_startup_parameters.h
+++ b/ios/chrome/browser/app_startup_parameters.h
@@ -8,7 +8,6 @@
 #import <Foundation/Foundation.h>
 
 class GURL;
-@class XCallbackParameters;
 
 // This class stores all the parameters relevant to the app startup in case
 // of launch from another app.
@@ -17,10 +16,6 @@ class GURL;
 // The URL received that should be opened.
 @property(nonatomic, readonly, assign) const GURL& externalURL;
 
-// Parameters representing an x-callback-url request from another app.
-// Can be nil.
-@property(nonatomic, readonly, strong) XCallbackParameters* xCallbackParameters;
-
 // Boolean to track if a voice search is requested at startup.
 @property(nonatomic, readwrite, assign) BOOL launchVoiceSearch;
 // Boolean to track if the app should launch in incognito mode.
@@ -32,10 +27,7 @@ class GURL;
 
 - (instancetype)init NS_UNAVAILABLE;
 
-- (instancetype)initWithExternalURL:(const GURL&)externalURL;
-
 - (instancetype)initWithExternalURL:(const GURL&)externalURL
-                xCallbackParameters:(XCallbackParameters*)xCallbackParameters
     NS_DESIGNATED_INITIALIZER;
 
 @end