[Mac] Move Back/Forward Touch Bar Icons 2 pts lower

chrome/browser/ui/cocoa/browser_window_touch_bar.mm

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/browser_window_touch_bar.h"
 
 #include <memory>
 
 #include "base/mac/foundation_util.h"
 #include "base/mac/mac_util.h"
@@ skipping 357 matching lines @@
                                    target:self
                                    action:@selector(exitFullscreenForTab:)]];
     [touchBar
         setTemplateItems:[NSSet setWithObject:touchBarItem.autorelease()]];
   }
 
   return touchBar.autorelease();
 }
 
 - (NSView*)backOrForwardTouchBarView {
-  NSArray* images = @[
+  NSMutableArray* images = [NSMutableArray arrayWithArray:@[
     CreateNSImageFromIcon(ui::kBackArrowIcon),
     CreateNSImageFromIcon(ui::kForwardArrowIcon)
-  ];
+  ]];
+
+  // Offset the icons so that it matches the height of the other Touch Bar
+  // items.
+  const int kIconYOffset = 2;
+  for (NSUInteger i = 0; i < [images count]; i++) {
+    NSImage* image = [images objectAtIndex:i];
+    NSSize size = [image size];
+    size.height += kIconYOffset;
+
+    NSImage* offsettedImage = [[[NSImage alloc] initWithSize:size] autorelease];
+    [offsettedImage lockFocus];
+    [image drawInRect:NSMakeRect(0, 0, size.width, size.height - kIconYOffset)];
+    [offsettedImage unlockFocus];
+    [images replaceObjectAtIndex:i withObject:offsettedImage];
+  }
 
   NSSegmentedControl* control = [NSSegmentedControl
       segmentedControlWithImages:images
                     trackingMode:NSSegmentSwitchTrackingMomentary
                           target:self
                           action:@selector(backOrForward:)];
   control.segmentStyle = NSSegmentStyleSeparated;
   [control setEnabled:commandUpdater_->IsCommandEnabled(IDC_BACK)
            forSegment:kBackSegmentIndex];
   [control setEnabled:commandUpdater_->IsCommandEnabled(IDC_FORWARD)
@@ skipping 70 matching lines @@
       ->ExitExclusiveAccessIfNecessary();
 }
 
 - (void)executeCommand:(id)sender {
   int command = [sender tag];
   LogTouchBarUMA(command);
   commandUpdater_->ExecuteCommand(command);
 }
 
 @end