Clean up SideSwipeView

This CL cleans up the SideSwipeView, moving from trailing underscore
for ivar to leading underscore. It also moves the ivar declaration from
the public header to the private implementation.

Bug: none
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I4310bbb9a078668d96720fd01111d3522418a7bb
Reviewed-on: https://chromium-review.googlesource.com/887201
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532357}

ios/chrome/browser/ui/side_swipe/card_side_swipe_view.h

@@ -13,32 +13,7 @@
 @protocol SideSwipeToolbarSnapshotProviding;
 @class TabModel;
 
-@interface SwipeView : UIView {
-  UIImageView* image_;
-  UIImageView* shadowView_;
-}
-@end
-
-@interface CardSideSwipeView : UIView {
-  // The direction of the swipe that initiated this horizontal view.
-  UISwipeGestureRecognizerDirection direction_;
-
-  // Card views currently displayed.
-  SwipeView* leftCard_;
-  SwipeView* rightCard_;
-
-  // Most recent touch location.
-  CGPoint currentPoint_;
-
-  // Space reserved at the top for the toolbar.
-  CGFloat topMargin_;
-
-  // Tab model.
-  __weak TabModel* model_;
-
-  // The image view containing the background image.
-  UIImageView* backgroundView_;
-}
+@interface CardSideSwipeView : UIView
 
 @property(nonatomic, weak) id<SideSwipeControllerDelegate> delegate;
 // Snapshot provider for the top toolbar.
@@ -47,11 +22,12 @@
 // Snapshot provider for the bottom toolbar.
 @property(nonatomic, weak) id<SideSwipeToolbarSnapshotProviding>
     bottomToolbarSnapshotProvider;
+// Space reserved at the top for the toolbar.
 @property(nonatomic, assign) CGFloat topMargin;
 
-- (id)initWithFrame:(CGRect)frame
-          topMargin:(CGFloat)margin
-              model:(TabModel*)model;
+- (instancetype)initWithFrame:(CGRect)frame
+                    topMargin:(CGFloat)margin
+                        model:(TabModel*)model;
 - (void)updateViewsForDirection:(UISwipeGestureRecognizerDirection)direction;
 - (void)handleHorizontalPan:(SideSwipeGestureRecognizer*)gesture;