[ios] BubbleViewController and BubbleView stubs.

ios/chrome/browser/ui/bubble_promo/bubble_view.mm

+// Copyright 2017 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 "ios/chrome/browser/ui/bubble_promo/bubble_view.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@interface BubbleView ()
+@property(nonatomic, readonly, weak) UILabel* label;

[edchin, 2017/07/07 04:24:10]

Remove readonly. You'll want to be able to set it. 

[gchatz, 2017/07/07 04:29:10]

Need comment here too.

[helenlyang, 2017/07/07 23:29:16]

My reasoning was that we want to modify the text, not the label itself.
I think we can still set label.text when label is readonly.
See NumberBadgeView:
https://cs.chromium.org/chromium/src/ios/chrome/browser/ui/reading_list/numbe...

[gchatz, 2017/07/08 00:39:48]

Overall with the label in NumberBadgeView, here is what is happening with its
object lifetime:
NumberBadgeView creates the label, stores it in a weak property, and adds it as
a subview of itself. The reason it is retained is because UIViews all have
strong references to its subviews. If the label is somehow removed from the view
hierarchy, then it will be deallocated and the |label| property becomes nil.

So, this set up is fine as long as there is no plan to remove the label from the
hierarchy and then use that instance again later. My guess is that they did not
make the label property strong because the same object (the UIView) would have a
two strong references to the same object (in the UIView superclass and in the
subclass).

+@end
+
+@implementation BubbleView
+
+@synthesize arrowDirection = _arrowDirection;
+@synthesize alignment = _alignment;
+@synthesize label = _label;
+
+- (instancetype)initWithText:(NSString*)text
+                   direction:(BubbleArrowDirection)arrowDirection
+                   alignment:(BubbleAlignment)alignment {
+  self = [super initWithFrame:CGRectZero];
+  return self;
+}
+

[edchin, 2017/07/07 04:24:10]

Add this line to document this section:
#pragma mark - UIView overrides

[helenlyang, 2017/07/07 23:29:15]

Done.

+- (CGSize)sizeThatFits:(CGSize)size {

[gchatz, 2017/07/07 04:29:10]

Should have comment explaining why override is happening.

[helenlyang, 2017/07/07 23:29:15]

Done.

+  return CGSizeZero;
+}
+
+@end