Make MdTextButton a LabelButton, use it in the DL shelf.

ui/views/controls/button/label_button.cc

 // 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.
 
 #include "ui/views/controls/button/label_button.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 75 matching lines @@
       cached_bold_font_list_(GetDefaultBoldFontList()),
       button_state_images_(),
       button_state_colors_(),
       explicitly_set_colors_(),
       is_default_(false),
       style_(STYLE_TEXTBUTTON),
       border_is_themed_border_(true),
       image_label_spacing_(kSpacing),
       horizontal_alignment_(gfx::ALIGN_LEFT) {
   SetAnimationDuration(kHoverAnimationDurationMs);
-  SetText(text);
+  SetTextInternal(text);
 
   AddChildView(ink_drop_container_);
   ink_drop_container_->SetPaintToLayer(true);
   ink_drop_container_->SetFillsBoundsOpaquely(false);
   ink_drop_container_->SetVisible(false);
 
   AddChildView(image_);
   image_->set_interactive(false);
 
   AddChildView(label_);
@@ skipping 17 matching lines @@
 void LabelButton::SetImage(ButtonState for_state, const gfx::ImageSkia& image) {
   button_state_images_[for_state] = image;
   UpdateImage();
 }
 
 const base::string16& LabelButton::GetText() const {
   return label_->text();
 }
 
 void LabelButton::SetText(const base::string16& text) {
-  SetAccessibleName(text);
-  label_->SetText(text);
+  SetTextInternal(text);
 }
 
 void LabelButton::SetTextColor(ButtonState for_state, SkColor color) {
   button_state_colors_[for_state] = color;
   if (for_state == STATE_DISABLED)
     label_->SetDisabledColor(color);
   else if (for_state == state())
     label_->SetEnabledColor(color);
   explicitly_set_colors_[for_state] = true;
 }
@@ skipping 13 matching lines @@
 }
 
 const gfx::FontList& LabelButton::GetFontList() const {
   return label_->font_list();
 }
 
 void LabelButton::SetFontList(const gfx::FontList& font_list) {
   cached_normal_font_list_ = font_list;
   cached_bold_font_list_ = font_list.DeriveWithStyle(
       font_list.GetFontStyle() | gfx::Font::BOLD);
-
-  // STYLE_BUTTON uses bold text to indicate default buttons.
-  label_->SetFontList(
-      style_ == STYLE_BUTTON && is_default_ ?
+  label_->SetFontList(is_default_ ?
       cached_bold_font_list_ : cached_normal_font_list_);
 }
 
 void LabelButton::SetElideBehavior(gfx::ElideBehavior elide_behavior) {
   label_->SetElideBehavior(elide_behavior);
 }
 
 void LabelButton::SetHorizontalAlignment(gfx::HorizontalAlignment alignment) {
   DCHECK_NE(gfx::ALIGN_TO_HEAD, alignment);
   horizontal_alignment_ = alignment;
   InvalidateLayout();
 }
 
 void LabelButton::SetMinSize(const gfx::Size& min_size) {
   min_size_ = min_size;
   ResetCachedPreferredSize();
 }
 
 void LabelButton::SetMaxSize(const gfx::Size& max_size) {
   max_size_ = max_size;
   ResetCachedPreferredSize();
 }
 
 void LabelButton::SetIsDefault(bool is_default) {
+  DCHECK_EQ(STYLE_BUTTON, style_);

[Evan Stade, 2016/03/08 02:04:15]

We don't call SetIsDefault for any STYLE_TEXTBUTTON button (I think --- trybots
are confirming). I'm hoping that when we switch everything to MD we can get rid
of LabelButton::SetStyle(). Then we'll have:

button = views::MdTextButton::Create();

instead of

button = new views::LabelButton();
button->SetStyle();

with a tall stack of DCHECKs in SetStyle. SetIsDefault would move to
MdTextButton also.

   if (is_default == is_default_)
     return;
+
   is_default_ = is_default;
   ui::Accelerator accel(ui::VKEY_RETURN, ui::EF_NONE);
   is_default_ ? AddAccelerator(accel) : RemoveAccelerator(accel);
 
-  // STYLE_BUTTON uses bold text to indicate default buttons.
-  if (style_ == STYLE_BUTTON) {
-    label_->SetFontList(
-        is_default ? cached_bold_font_list_ : cached_normal_font_list_);
-    InvalidateLayout();
-  }
+  label_->SetFontList(
+      is_default ? cached_bold_font_list_ : cached_normal_font_list_);
+  InvalidateLayout();
 }
 
 void LabelButton::SetStyle(ButtonStyle style) {
   // All callers currently pass STYLE_BUTTON, and should only call this once, to
   // change from the default style.
   DCHECK_EQ(style, STYLE_BUTTON);
   DCHECK_EQ(style_, STYLE_TEXTBUTTON);
   DCHECK(!GetWidget()) << "Can't change button style after adding to a Widget.";
 
   style_ = style;
@@ skipping 295 matching lines @@
 
 void LabelButton::UpdateThemedBorder() {
   // Don't override borders set by others.
   if (!border_is_themed_border_)
     return;
 
   SetBorder(PlatformStyle::CreateThemedLabelButtonBorder(this));
   border_is_themed_border_ = true;
 }
 
+void LabelButton::SetTextInternal(const base::string16& text) {
+  SetAccessibleName(text);
+  label_->SetText(text);
+}
+
 void LabelButton::ChildPreferredSizeChanged(View* child) {
   ResetCachedPreferredSize();
   PreferredSizeChanged();
 }
 
 ui::NativeTheme::Part LabelButton::GetThemePart() const {
   return ui::NativeTheme::kPushButton;
 }
 
 gfx::Rect LabelButton::GetThemePaintRect() const {
@@ skipping 28 matching lines @@
   GetExtraParams(params);
   return ui::NativeTheme::kHovered;
 }
 
 void LabelButton::ResetCachedPreferredSize() {
   cached_preferred_size_valid_ = false;
   cached_preferred_size_ = gfx::Size();
 }
 
 }  // namespace views