Don't use dashed focus painter on back button in MD mode.

chrome/browser/ui/views/toolbar/back_button.cc

Index: chrome/browser/ui/views/toolbar/back_button.cc
diff --git a/chrome/browser/ui/views/toolbar/back_button.cc b/chrome/browser/ui/views/toolbar/back_button.cc
index f713da2bd9f9f282a2956b02666bf354a6b2f286..b39510683f84315158db586f1d5fcb01093f73b2 100644
--- a/chrome/browser/ui/views/toolbar/back_button.cc
+++ b/chrome/browser/ui/views/toolbar/back_button.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/ui/views/toolbar/back_button.h"
 
+#include "ui/base/material_design/material_design_controller.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/views/animation/ink_drop.h"
 #include "ui/views/controls/button/label_button_border.h"
@@ -21,11 +22,13 @@ void BackButton::SetLeadingMargin(int margin) {
 
   UpdateThemedBorder();
 
-  const int inset = LabelButton::kFocusRectInset;
-  const bool is_rtl = base::i18n::IsRTL();
-  const gfx::Insets insets(inset, inset + (is_rtl ? 0 : margin),
-                           inset, inset + (is_rtl ? margin : 0));
-  SetFocusPainter(views::Painter::CreateDashedFocusPainterWithInsets(insets));
+  if (!ui::MaterialDesignController::IsModeMaterial()) {

[Peter Kasting, 2016/06/14 22:11:57]

Heh, I'd been thinking to have both conditions here, but since the other
condition should always be true pre-MD, your way is better.

+    const int inset = LabelButton::kFocusRectInset;
+    const bool is_rtl = base::i18n::IsRTL();
+    const gfx::Insets insets(inset, inset + (is_rtl ? 0 : margin),
+                             inset, inset + (is_rtl ? margin : 0));
+    SetFocusPainter(views::Painter::CreateDashedFocusPainterWithInsets(insets));
+  }
   InvalidateLayout();
 }