Add a fake cursor (blinking UIView) to the widget extension.

ios/chrome/widget_extension/widget_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/widget_extension/widget_view.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
+@interface WidgetView ()
+
+@property(nonatomic, weak) UIView* cursor;
+
+@end
+
 @implementation WidgetView
 
-#pragma mark - Lifecycle
+@synthesize cursor = _cursor;
 
 - (instancetype)init {
   self = [super initWithFrame:CGRectZero];
+  if (self) {
+    [self addCursor];
+  }
   return self;
 }
 
+- (void)addCursor {

[Olivier, 2017/01/19 10:33:07]

declare method and add comment.
Document that it sets the property of the class.

[lody, 2017/01/19 13:17:55]

Done.

+  UIView* cursor = [[UIView alloc] initWithFrame:CGRectZero];

[Olivier, 2017/01/19 10:33:07]

Is the cursor added directly in the widget view?
Should there be a fake input box around the fake cursor?

[lody, 2017/01/19 13:17:55]

Some of the current mocks say yes, some say no. I stuck with no for now (the
screenshot issue continues to exist with the animated cursor, so this is the
minimum necessary to see it happen.)

+  self.cursor = cursor;
+  self.cursor.backgroundColor = [UIColor blueColor];
+  [self addSubview:_cursor];

[Olivier, 2017/01/19 10:33:07]

cursor or self.cursor

[lody, 2017/01/19 13:17:55]

Done.

+
+  [self.cursor setTranslatesAutoresizingMaskIntoConstraints:NO];
+  [NSLayoutConstraint activateConstraints:@[
+    [[self.cursor widthAnchor] constraintEqualToConstant:2],
+    [[self.cursor leadingAnchor] constraintEqualToAnchor:self.leadingAnchor
+                                                constant:40],
+    [[self.cursor heightAnchor] constraintEqualToConstant:40],
+    [[self.cursor centerYAnchor] constraintEqualToAnchor:self.centerYAnchor]
+  ]];
+
+  [UIView animateWithDuration:0.3
+                        delay:0.0
+                      options:UIViewAnimationOptionRepeat |
+                              UIViewAnimationOptionAutoreverse
+                   animations:^{
+                     self.cursor.alpha = 0.0f;
+                   }
+                   completion:nil];
+}
+
 @end