[ios] Adds safeAreaInsets to HistoryCollectionVC

Bug: 802820
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I69d9bc940dc4c3be546dcf283a7463e20800cf10
Reviewed-on: https://chromium-review.googlesource.com/884568
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Reviewed-by: Louis Romero <lpromero@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531925}

ios/chrome/browser/ui/history/history_collection_view_controller.mm

@@ -221,6 +221,17 @@ const CGFloat kSeparatorInset = 10;
   [self.collectionView addGestureRecognizer:longPressRecognizer];
 }
 
+// Since contentInsetAdjustmentBehavior is
+// UIScrollViewContentInsetAdjustmentNever on iOS11, update the horizontal
+// insets manually to respect the safeArea.
+- (void)viewSafeAreaInsetsDidChange {
+  [super viewSafeAreaInsetsDidChange];
+  UIEdgeInsets collectionContentInsets = self.collectionView.contentInset;
+  collectionContentInsets.left = self.view.safeAreaInsets.left;
+  collectionContentInsets.right = self.view.safeAreaInsets.right;
+  self.collectionView.contentInset = collectionContentInsets;
+}
+
 - (BOOL)isEditing {
   return self.editor.isEditing;
 }