[Mac][Material Design] Fix toolbar height on Retina.

chrome/browser/ui/cocoa/toolbar/toolbar_controller.mm

 // Copyright (c) 2012 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/toolbar/toolbar_controller.h"
 
 #include <algorithm>
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/foundation_util.h"
@@ skipping 1037 matching lines @@
 - (NSPoint)saveCreditCardBubblePoint {
   return locationBarView_->GetSaveCreditCardBubblePoint();
 }
 
 - (NSPoint)translateBubblePoint {
   return locationBarView_->GetTranslateBubblePoint();
 }
 
 - (CGFloat)baseToolbarHeight {
   // Height of the toolbar in pixels when the bookmark bar is closed.
-  const CGFloat baseToolbarHeightNormal =
-      ui::MaterialDesignController::IsModeMaterial() ? 37 : 35;
+  const bool kIsModeMaterial = ui::MaterialDesignController::IsModeMaterial();
+  const CGFloat kBaseToolbarHeightNormal = kIsModeMaterial ? 37 : 35;
 
   // Not all lines are drawn at 2x normal height when running on Retina, which
   // causes the toolbar controls to be visually 1pt too high within the toolbar
   // area. It's not possible to adjust the control y-positions by 0.5pt and have
   // them appear 0.5pt lower (they are still drawn at their original locations),
   // so instead shave off 1pt from the bottom of the toolbar. Note that there's
   // an offsetting change in -[BookmarkBarController preferredHeight] to
   // maintain the proper spacing between bookmark icons and toolbar items. See
   // https://crbug.com/326245 .
-  return [[self view] cr_lineWidth] == 0.5 ? baseToolbarHeightNormal - 1
-                                           : baseToolbarHeightNormal;
+  const CGFloat kLineWidth = [[self view] cr_lineWidth];
+  const BOOL kIsRetina = (kLineWidth < 1);
+  BOOL reduceHeight = YES;
+
+  // If Material Design and Retina, no height adjustment is needed.
+  if (kIsModeMaterial && kIsRetina) {
+    reduceHeight = NO;
+  }
+
+  return reduceHeight ? kBaseToolbarHeightNormal - 1
+                      : kBaseToolbarHeightNormal;
 }
 
 - (CGFloat)desiredHeightForCompression:(CGFloat)compressByHeight {
   // With no toolbar, just ignore the compression.
   if (!hasToolbar_)
     return NSHeight([locationBar_ frame]);
 
   return [self baseToolbarHeight] - compressByHeight;
 }
 
@@ skipping 70 matching lines @@
 - (void)hideDropURLsIndicatorInView:(NSView*)view {
   // Do nothing.
 }
 
 // (URLDropTargetController protocol)
 - (BOOL)isUnsupportedDropData:(id<NSDraggingInfo>)info {
   return drag_util::IsUnsupportedDropData(profile_, info);
 }
 
 @end