[AF] Fixes the scrolling problem with the FormSuggestionView

Bug: 792879
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Ic86fa2a72adeab804c22a62efa9b291408e5b482
Reviewed-on: https://chromium-review.googlesource.com/827725Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524396}

ios/chrome/browser/autofill/form_suggestion_view.mm

@@ -71,10 +71,12 @@ const CGFloat kSuggestionHorizontalMargin = 6;
   return self;
 }
 
-- (void)setFrame:(CGRect)frame {
-  [super setFrame:frame];
+- (void)layoutSubviews {
+  [super layoutSubviews];
 
-  CGFloat contentwidth = kSuggestionHorizontalMargin * 2;
+  CGRect frame = self.frame;
+
+  CGFloat contentwidth = kSuggestionHorizontalMargin;
   for (UIView* label in self.subviews) {
     contentwidth += CGRectGetWidth([label frame]) + kSuggestionHorizontalMargin;
   }