[iOS][MF] Update cell paddings

Increased the section header.
Decreased the section footer.
Increased the space between title and top of the cells.

Bug: 949060
Change-Id: I48501c665d7ff77388171bb0ac7bbf43ae23b976
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1865328
Auto-Submit: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Commit-Queue: Olivier Robin <olivierrobin@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707804}

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

@@ -38,6 +38,12 @@ constexpr CGFloat PopoverLoadingHeight = 185.5;
 // amount of seconds.
 constexpr CGFloat kMinimumLoadingTime = 0.5;
 
+// Height of the section header.
+constexpr CGFloat kSectionHeaderHeight = 6;
+
+// Height of the section footer.
+constexpr CGFloat kSectionFooterHeight = 14;
+
 }  // namespace
 
 @interface FallbackViewController ()
@@ -83,8 +89,8 @@ constexpr CGFloat kMinimumLoadingTime = 0.5;
   [super viewDidLoad];
 
   self.tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
-  self.tableView.sectionHeaderHeight = 0;
-  self.tableView.sectionFooterHeight = 20.0;
+  self.tableView.sectionHeaderHeight = kSectionHeaderHeight;
+  self.tableView.sectionFooterHeight = kSectionFooterHeight;
   self.tableView.estimatedRowHeight = 1;
   self.tableView.separatorInset = UIEdgeInsetsMake(0, 0, 0, 0);
   self.tableView.allowsSelection = NO;

ios/chrome/browser/ui/autofill/manual_fill/manual_fill_cell_utils.h

@@ -16,7 +16,7 @@ static const CGFloat kButtonHorizontalMargin = 16;
 static const CGFloat kChipsHorizontalMargin = -1;
 
 // The multiplier for the base system spacing at the top margin.
-static const CGFloat TopSystemSpacingMultiplier = 1.58;
+static const CGFloat TopSystemSpacingMultiplier = 2;
 
 // The multiplier for the base system spacing at the bottom margin.
 static const CGFloat BottomSystemSpacingMultiplier = 2.26;