[iOS][MF] Add more spacing on iPads

The space was modifidied in order to match Apple's next and previous
arrows below them.

Bug: 912551
Change-Id: I41955034a9b9af396ef710dbb494d5a97bbc799f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1505946
Commit-Queue: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638251}

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

@@ -31,11 +31,20 @@ NSString* const AccessoryCreditCardAccessibilityIdentifier =
 
 namespace {
 
-// The inset on the left before the icons start.
-constexpr CGFloat ManualFillIconsLeftInset = 10;
+// The leading inset for the icons.
+constexpr CGFloat ManualFillIconsLeadingInset = 10;
 
-// The inset on the right after the icons end.
-constexpr CGFloat ManualFillIconsRightInset = 24;
+// The trailing inset for the icons.
+constexpr CGFloat ManualFillIconsTrailingInset = 24;
+
+// The iPad override for the trailing inset.
+constexpr CGFloat ManualFillIconsIPadTrailingInset = 20;
+
+// Default spacing for the icons.
+constexpr CGFloat ManualFillIconsSpacing = 10;
+
+// iPad override for the icons' spacing.
+constexpr CGFloat ManualFillIconsIPadSpacing = 15;
 
 }  // namespace
 
@@ -190,11 +199,14 @@ static NSTimeInterval MFAnimationDuration = 0.2;
     [icons addObject:self.accountButton];
   }
   UIStackView* stackView = [[UIStackView alloc] initWithArrangedSubviews:icons];
-  stackView.spacing = 10;
+  stackView.spacing =
+      IsIPadIdiom() ? ManualFillIconsIPadSpacing : ManualFillIconsSpacing;
   stackView.axis = UILayoutConstraintAxisHorizontal;
   stackView.translatesAutoresizingMaskIntoConstraints = NO;
   [self.view addSubview:stackView];
 
+  CGFloat trailingInset = IsIPadIdiom() ? ManualFillIconsIPadTrailingInset
+                                        : ManualFillIconsTrailingInset;
   id<LayoutGuideProvider> safeAreaLayoutGuide = self.view.safeAreaLayoutGuide;
   [NSLayoutConstraint activateConstraints:@[
     // Vertical constraints.
@@ -204,10 +216,10 @@ static NSTimeInterval MFAnimationDuration = 0.2;
     // Horizontal constraints.
     [stackView.leadingAnchor
         constraintEqualToAnchor:safeAreaLayoutGuide.leadingAnchor
-                       constant:ManualFillIconsLeftInset],
+                       constant:ManualFillIconsLeadingInset],
     [safeAreaLayoutGuide.trailingAnchor
         constraintEqualToAnchor:stackView.trailingAnchor
-                       constant:ManualFillIconsRightInset],
+                       constant:trailingInset],
   ]];
 }