[iOS] Stop swizzling the |init| method of CameraController.

ios/chrome/browser/ui/qr_scanner/qr_scanner_view_controller_egtest.mm

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import <AVFoundation/AVFoundation.h>
 #import <EarlGrey/EarlGrey.h>
 #import <UIKit/UIKit.h>
 
 #import "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 378 matching lines @@
 }
 
 #pragma mark -
 #pragma mark Helpers for mocks
 
 // Swizzles the CameraController method cameraControllerWithDelegate: to return
 // |cameraControllerMock| instead of a new instance of CameraController.
 - (void)swizzleCameraController:(id)cameraControllerMock {
   CameraController* (^swizzleCameraControllerBlock)(
       id<CameraControllerDelegate>) = ^(id<CameraControllerDelegate> delegate) {
-    // |initWithDelegate:| must return an object with a return count of 1
-    // because it is preceded by a call to |alloc|.
-    return [cameraControllerMock retain];
+    return cameraControllerMock;
   };
 
   camera_controller_swizzler_.reset(new ScopedBlockSwizzler(
-      [CameraController class], @selector(initWithDelegate:),
+      [CameraController class], @selector(cameraControllerWithDelegate:),
       swizzleCameraControllerBlock));
 }
 
 // Swizzles the WebToolbarController loadGURLFromLocationBarBlock:transition:
 // method to load |searchURL| instead of the generated search URL.
 - (void)swizzleWebToolbarControllerLoadGURLFromLocationBar:
     (const GURL&)searchURL {
   void (^loadGURLFromLocationBarBlock)(WebToolbarController*, const GURL&,
                                        ui::PageTransition) =
       ^void(WebToolbarController* self, const GURL& url,
@@ skipping 402 matching lines @@
 // Test that the correct page is loaded if the scanner result is a search query
 // which is then manually edited.
 - (void)testReceivingQRScannerSearchQueryResultAndEditingTheQuery {
   [self swizzleWebToolbarControllerLoadGURLFromLocationBar:_testQueryEdited];
   [self doTestReceivingResult:kTestQuery
                      response:kTestQueryEditedResponse
                          edit:@"\bedited"];
 }
 
 @end