Draw infobar arrow border with width of 1px on any scale factor.

chrome/browser/ui/infobar_container_delegate.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_UI_INFOBAR_CONTAINER_DELEGATE_H_
 #define CHROME_BROWSER_UI_INFOBAR_CONTAINER_DELEGATE_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "components/infobars/core/infobar_container.h"
 
 class InfoBarContainerDelegate : public infobars::InfoBarContainer::Delegate {
  public:
+  // TODO(estade): make some or all of these private.
   static const int kDefaultBarTargetHeight;
   static const int kDefaultBarTargetHeightMd;
   static const int kSeparatorLineHeight;
   static const int kDefaultArrowTargetHeight;
+  static const int kDefaultArrowTargetHeightMd;
   static const int kMaximumArrowTargetHeight;
   static const int kDefaultArrowTargetHalfWidth;
+  static const int kDefaultArrowTargetHalfWidthMd;
   static const int kMaximumArrowTargetHalfWidth;
 
   InfoBarContainerDelegate();
   ~InfoBarContainerDelegate() override;
 
   // Called when the distance between what the top infobar's "unspoofable" arrow
   // would point to and the top infobar itself changes.  Sets the maximum height
   // of the top arrow to the new |height| and asks |container| to update its
   // infobars accordingly.  This enables the top infobar to show a longer arrow
   // (e.g. because of a visible bookmark bar) or shorter (e.g. due to being in a
@@ skipping 11 matching lines @@
                                   int* arrow_half_width,
                                   int* bar_height) const override;
 
  private:
   int top_arrow_target_height_;
 
   DISALLOW_COPY_AND_ASSIGN(InfoBarContainerDelegate);
 };
 
 #endif  // CHROME_BROWSER_UI_INFOBAR_CONTAINER_DELEGATE_H_