Clean-up: Avoids unnecessary font list creation in views::Tab.

ui/views/controls/tabbed_pane/tabbed_pane.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/tabbed_pane/tabbed_pane.h"
 
 #include "base/logging.h"
 #include "ui/base/accessibility/accessible_view_state.h"
+#include "ui/base/resource/resource_bundle.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/font_list.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/controls/tabbed_pane/tabbed_pane_listener.h"
 #include "ui/views/layout/layout_manager.h"
 #include "ui/views/widget/widget.h"
 
 namespace {
 
@@ skipping 133 matching lines @@
   bounds.Inset(0, 1, 0, 0);
   bounds.ClampToCenteredSize(preferred_title_size_);
   title_->SetBoundsRect(bounds);
 }
 
 void Tab::SetState(TabState tab_state) {
   if (tab_state == tab_state_)
     return;
   tab_state_ = tab_state;
 
+  ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
   switch (tab_state) {
     case TAB_INACTIVE:
       title_->SetEnabledColor(kTabTitleColor_Inactive);
-      title_->SetFontList(gfx::FontList());
+      title_->SetFontList(rb.GetFontList(ui::ResourceBundle::BaseFont));

[sadrul, 2014/01/16 14:29:41]

Just so I understand: this (and the change in line 175) are no-ops, right?

[Yuki, 2014/01/16 14:53:27]

My understanding is that
1. When Tab::SetState(TAB_ACTIVE) is called,
   we do title_->SetFontList(BoldFont);
2. When Tab::SetState(TAB_INACTIVE) is called after 1.,
   we *reset* title_->SetFontList(BaseFont);

So, 2. is not no-op.  It resets to the base (non-bold) font list.  It's
necessary.

[sadrul, 2014/01/16 15:17:31]

I was not asking whether it was necessary to call SetFontList. I was asking if
the change from gfx::FontList() to GetFontList(Base) is a no-op (I remember in
an earlier CL someone mentioned that they are equivalent).

[Yuki, 2014/01/16 15:31:02]

Yes, they're equivalent.  The default instance of FontList is the same as
BaseFont, except that ui::ResourceBundle::GetFontList() does not create a new
instance of FontList.

       break;
     case TAB_ACTIVE:
       title_->SetEnabledColor(kTabTitleColor_Active);
-      title_->SetFontList(
-          gfx::FontList().DeriveFontListWithSizeDeltaAndStyle(
-              0, gfx::Font::BOLD));
+      title_->SetFontList(rb.GetFontList(ui::ResourceBundle::BoldFont));
       break;
     case TAB_HOVERED:
       title_->SetEnabledColor(kTabTitleColor_Hovered);
-      title_->SetFontList(gfx::FontList());
+      title_->SetFontList(rb.GetFontList(ui::ResourceBundle::BaseFont));
       break;
   }
   SchedulePaint();
 }
 
 TabStrip::TabStrip(TabbedPane* tabbed_pane) : tabbed_pane_(tabbed_pane) {}
 
 TabStrip::~TabStrip() {}
 
 gfx::Size TabStrip::GetPreferredSize() {
@@ skipping 180 matching lines @@
     selected_tab->NotifyAccessibilityEvent(
         ui::AccessibilityTypes::EVENT_FOCUS, true);
   }
 }
 
 void TabbedPane::GetAccessibleState(ui::AccessibleViewState* state) {
   state->role = ui::AccessibilityTypes::ROLE_PAGETABLIST;
 }
 
 }  // namespace views