Refactor MdFocusRing to make it easier to reuse on other controls.

ui/views/controls/textfield/textfield.cc

Index: ui/views/controls/textfield/textfield.cc
diff --git a/ui/views/controls/textfield/textfield.cc b/ui/views/controls/textfield/textfield.cc
index 4642d23fc89a89633cc84ff72fbb5011959a7b9d..3639b883b68735affec8e871bbb517c0d9018645 100644
--- a/ui/views/controls/textfield/textfield.cc
+++ b/ui/views/controls/textfield/textfield.cc
@@ -33,6 +33,7 @@
 #include "ui/native_theme/native_theme.h"
 #include "ui/strings/grit/ui_strings.h"
 #include "ui/views/background.h"
+#include "ui/views/controls/focus_ring.h"
 #include "ui/views/controls/focusable_border.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/controls/menu/menu_runner.h"
@@ -260,12 +261,17 @@ Textfield::Textfield()
       aggregated_clicks_(0),
       drag_start_display_offset_(0),
       touch_handles_hidden_due_to_scroll_(false),
+      focus_ring_(nullptr),
       weak_ptr_factory_(this) {
   set_context_menu_controller(this);
   set_drag_controller(this);
   GetRenderText()->SetFontList(GetDefaultFontList());
   SetBorder(std::unique_ptr<Border>(new FocusableBorder()));
   SetFocusBehavior(FocusBehavior::ALWAYS);
+  if (ui::MaterialDesignController::IsSecondaryUiMaterial()) {
+    focus_ring_ = new FocusRing();
+    AddChildView(focus_ring_);
+  }
 
   // These allow BrowserView to pass edit commands from the Chrome menu to us
   // when we're focused by simply asking the FocusManager to
@@ -990,6 +996,8 @@ void Textfield::OnFocus() {
     StartBlinkingCursor();
   View::OnFocus();
   SchedulePaint();
+  if (ui::MaterialDesignController::IsSecondaryUiMaterial())
+    focus_ring_->SetVisible(true);
 }
 
 void Textfield::OnBlur() {
@@ -1007,6 +1015,8 @@ void Textfield::OnBlur() {
 
   // Border typically draws focus indicator.
   SchedulePaint();
+  if (ui::MaterialDesignController::IsSecondaryUiMaterial())
+    focus_ring_->SetVisible(false);

[sky, 2016/10/03 23:53:15]

Similar comment about deleting here.

 }
 
 gfx::Point Textfield::GetKeyboardContextMenuLocation() {