[ios] Active web state observer in tab collection.

ios/clean/chrome/browser/ui/tab_collection/tab_collection_tab_cell.mm

Index: ios/clean/chrome/browser/ui/tab_collection/tab_collection_tab_cell.mm
diff --git a/ios/clean/chrome/browser/ui/tab_collection/tab_collection_tab_cell.mm b/ios/clean/chrome/browser/ui/tab_collection/tab_collection_tab_cell.mm
index f904ac56ee1d5229e3f69bb26a986fe0b6aeb158..ff06540ac84a353c9dc155b06eae63e9e61016f7 100644
--- a/ios/clean/chrome/browser/ui/tab_collection/tab_collection_tab_cell.mm
+++ b/ios/clean/chrome/browser/ui/tab_collection/tab_collection_tab_cell.mm
@@ -9,6 +9,7 @@
 #endif
 
 namespace {
+const CGFloat kBorderMargin = 6.0f;
 const CGFloat kSelectedBorderCornerRadius = 8.0f;
 const CGFloat kSelectedBorderWidth = 4.0f;
 }
@@ -17,16 +18,36 @@ const CGFloat kSelectedBorderWidth = 4.0f;
 
 - (instancetype)initWithFrame:(CGRect)frame {
   if ((self = [super initWithFrame:frame])) {
-    self.selectedBackgroundView = [[UIView alloc] init];
-    self.selectedBackgroundView.backgroundColor = [UIColor blackColor];
-    self.selectedBackgroundView.layer.cornerRadius =
-        kSelectedBorderCornerRadius;
-    self.selectedBackgroundView.layer.borderWidth = kSelectedBorderWidth;
-    self.selectedBackgroundView.layer.borderColor = self.tintColor.CGColor;
-    self.selectedBackgroundView.transform = CGAffineTransformScale(
-        self.selectedBackgroundView.transform, 1.08, 1.08);
+    [self setupSelectedBackgroundView];
   }
   return self;
 }
 
+- (void)setupSelectedBackgroundView {

[marq (ping after 24h), 2017/05/30 11:09:43]

This is fine for this CL, but consider getting in the habit of keeping the
changes in each CL logically grouped. This fix is small and would have landed
quickly as an independent CL.

[edchin, 2017/06/01 23:52:28]

Acknowledged.

+  self.selectedBackgroundView = [[UIView alloc] init];
+  self.selectedBackgroundView.backgroundColor = [UIColor blackColor];
+
+  UIView* border = [[UIView alloc] init];
+  border.translatesAutoresizingMaskIntoConstraints = NO;
+  border.backgroundColor = [UIColor blackColor];
+  border.layer.cornerRadius = kSelectedBorderCornerRadius;
+  border.layer.borderWidth = kSelectedBorderWidth;
+  border.layer.borderColor = self.tintColor.CGColor;
+  [self.selectedBackgroundView addSubview:border];
+  [NSLayoutConstraint activateConstraints:@[
+    [border.topAnchor
+        constraintEqualToAnchor:self.selectedBackgroundView.topAnchor
+                       constant:-kBorderMargin],
+    [border.leadingAnchor
+        constraintEqualToAnchor:self.selectedBackgroundView.leadingAnchor
+                       constant:-kBorderMargin],
+    [border.trailingAnchor
+        constraintEqualToAnchor:self.selectedBackgroundView.trailingAnchor
+                       constant:kBorderMargin],
+    [border.bottomAnchor
+        constraintEqualToAnchor:self.selectedBackgroundView.bottomAnchor
+                       constant:kBorderMargin]
+  ]];
+}
+
 @end