[iOS] Cleanup CRWTouchTrackingRecognizer delegates name

This CL changes the names of the touch tracking recognizers delegates
name. The gesture recognizer has two delegates:
 1. The UIGestureRecognizerDelegate (self.delegate)
 2. The CRWTouchTrackingDelegate (self.touchTrackingDelegate)
Prior to this CL, 1. was called using self.delegate and 2. was called
using _delegate. This was very confusing as the reader could expect
_delegate to be the ivar associated with self.delegate, not with
self.touchTrackingDelegate.

This CL cleans this by changing _delegate into _touchTrackingDelegate.

Bug: none
Change-Id: I24331d455f8cea61c117ea698e06f26fbc13ca6d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1732083
Auto-Submit: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Eugene But <eugenebut@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683622}

ios/web/web_state/ui/crw_touch_tracking_recognizer.h

@@ -24,7 +24,8 @@
 @property(nonatomic, weak) id<CRWTouchTrackingDelegate> touchTrackingDelegate;
 
 // Designated initializer for CRWTouchTrackingRecognizer.
-- (id)initWithDelegate:(id<CRWTouchTrackingDelegate>)delegate;
+- (id)initWithTouchTrackingDelegate:
+    (id<CRWTouchTrackingDelegate>)touchTrackingDelegate;
 
 @end
 

ios/web/web_state/ui/crw_touch_tracking_recognizer.mm

@@ -8,18 +8,15 @@
 #error "This file requires ARC support."
 #endif
 
-@interface CRWTouchTrackingRecognizer () <UIGestureRecognizerDelegate> {
-  id<CRWTouchTrackingDelegate> __weak _delegate;
-}
+@interface CRWTouchTrackingRecognizer () <UIGestureRecognizerDelegate>
 @end
 
 @implementation CRWTouchTrackingRecognizer
 
-@synthesize touchTrackingDelegate = _delegate;
-
-- (id)initWithDelegate:(id<CRWTouchTrackingDelegate>)delegate {
+- (id)initWithTouchTrackingDelegate:
+    (id<CRWTouchTrackingDelegate>)touchTrackingDelegate {
   if ((self = [super init])) {
-    _delegate = delegate;
+    _touchTrackingDelegate = touchTrackingDelegate;
     self.delegate = self;
   }
   return self;
@@ -34,7 +31,7 @@
 
 - (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event {
   [super touchesBegan:touches withEvent:event];
-  [_delegate touched:YES];
+  [self.touchTrackingDelegate touched:YES];
 }
 
 - (void)touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event {
@@ -44,12 +41,12 @@
 - (void)touchesEnded:(NSSet*)touches withEvent:(UIEvent*)event {
   [super touchesEnded:touches withEvent:event];
   self.state = UIGestureRecognizerStateFailed;
-  [_delegate touched:NO];
+  [self.touchTrackingDelegate touched:NO];
 }
 
 - (void)touchesCancelled:(NSSet*)touches withEvent:(UIEvent*)event {
   [super touchesCancelled:touches withEvent:event];
-  [_delegate touched:NO];
+  [self.touchTrackingDelegate touched:NO];
 }
 
 #pragma mark -

ios/web/web_state/ui/crw_web_controller.mm

@@ -539,7 +539,7 @@ typedef void (^ViewportStateCompletion)(const web::PageViewportState*);
 - (CRWTouchTrackingRecognizer*)touchTrackingRecognizer {
   if (!_touchTrackingRecognizer) {
     _touchTrackingRecognizer =
-        [[CRWTouchTrackingRecognizer alloc] initWithDelegate:self];
+        [[CRWTouchTrackingRecognizer alloc] initWithTouchTrackingDelegate:self];
   }
   return _touchTrackingRecognizer;
 }