views: reduce focus halo thickness to 2dip

This change reduces focus rings from 4dip thick inset by 2dip to 2dip thick inset
by 1dip.

Bug: 851122
Change-Id: I8e38df43fd410cb4f1dc526c767b4f77b26733cd
Reviewed-on: https://chromium-review.googlesource.com/1127929
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#573381}

ui/views/style/platform_style.cc

@@ -42,8 +42,8 @@ const bool PlatformStyle::kIsOkButtonLeading = false;
 
 // Set kFocusHaloInset to negative half of kFocusHaloThickness to draw half of
 // the focus ring inside and half outside the parent elmeent
-const float PlatformStyle::kFocusHaloThickness = 4.f;
-const float PlatformStyle::kFocusHaloInset = -2.f;
+const float PlatformStyle::kFocusHaloThickness = 2.f;
+const float PlatformStyle::kFocusHaloInset = -1.f;
 
 #if !defined(OS_MACOSX)