[iOS][MF] Fix content instets on rotation

Bug: 845472
Change-Id: I3afc1e03c280c88cce039ac8d4a6b288edd7be78
Reviewed-on: https://chromium-review.googlesource.com/c/1355173
Reviewed-by: Yi Su <mrsuyi@chromium.org>
Commit-Queue: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#612608}(cherry picked from commit 39cf762)
Reviewed-on: https://chromium-review.googlesource.com/c/1363176
Reviewed-by: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Cr-Commit-Position: refs/branch-heads/3626@{#72}
Cr-Branched-From: d897fb1-refs/heads/master@{#612437}

Author: Javier Ernesto Flores Robles

ios/chrome/browser/ui/autofill/manual_fill/fallback_view_controller.mm

@@ -104,7 +104,7 @@ - (void)handleKeyboardDidHide:(NSNotification*)notification {
   if (self.contentInsetsAlwaysEqualToSafeArea && !IsIPadIdiom()) {
     // Resets the table view content inssets to be equal to the safe area
     // insets.
-    self.tableView.contentInset = self.view.safeAreaInsets;
+    self.tableView.contentInset = UIEdgeInsetsZero;
   }
 }
 
@@ -117,9 +117,9 @@ - (void)handleKeyboardWillShow:(NSNotification*)notification {
         [notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
     CGFloat keyboardHeight = keyboardFrame.size.height;
     UIEdgeInsets safeInsets = self.view.safeAreaInsets;
+    // |contentInset| already contemplates the safe area.
     self.tableView.contentInset =
-        UIEdgeInsetsMake(safeInsets.top, safeInsets.left,
-                         safeInsets.bottom - keyboardHeight, safeInsets.right);
+        UIEdgeInsetsMake(0, 0, safeInsets.bottom - keyboardHeight, 0);
   }
 }