Remove Label::PaintText overrides.

ash/accelerators/exit_warning_handler.cc

 // Copyright 2013 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 "ash/accelerators/exit_warning_handler.h"
 
 #include "ash/metrics/user_metrics_recorder.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "ash/shell_window_ids.h"
@@ skipping 20 matching lines @@
 const int64 kTimeOutMilliseconds = 2000;
 // Color of the text of the warning message.
 const SkColor kTextColor = SK_ColorWHITE;
 // Color of the window background.
 const SkColor kWindowBackgroundColor = SkColorSetARGB(0xC0, 0x0, 0x0, 0x0);
 // Radius of the rounded corners of the window.
 const int kWindowCornerRadius = 2;
 const int kHorizontalMarginAroundText = 100;
 const int kVerticalMarginAroundText = 100;
 
-class ExitWarningLabel : public views::Label {
- public:
-  ExitWarningLabel() {}
-
-  virtual ~ExitWarningLabel() {}
-
- private:
-  virtual void PaintText(gfx::Canvas* canvas,
-                         const base::string16& text,
-                         const gfx::Rect& text_bounds,
-                         int flags) OVERRIDE {
-    // Turn off subpixel rendering.
-    views::Label::PaintText(canvas,
-                            text,
-                            text_bounds,
-                            flags | gfx::Canvas::NO_SUBPIXEL_RENDERING);
-  }
-
-  DISALLOW_COPY_AND_ASSIGN(ExitWarningLabel);
-};
-
 class ExitWarningWidgetDelegateView : public views::WidgetDelegateView {
  public:
   ExitWarningWidgetDelegateView() : text_width_(0), width_(0), height_(0) {
 #ifdef OS_CHROMEOS
     text_ = l10n_util::GetStringUTF16(IDS_ASH_SIGN_OUT_WARNING_POPUP_TEXT);
     accessible_name_ = l10n_util::GetStringUTF16(
         IDS_ASH_SIGN_OUT_WARNING_POPUP_TEXT_ACCESSIBLE);
 #else
     text_ = l10n_util::GetStringUTF16(IDS_ASH_EXIT_WARNING_POPUP_TEXT);
     accessible_name_ =
         l10n_util::GetStringUTF16(IDS_ASH_EXIT_WARNING_POPUP_TEXT_ACCESSIBLE);
 #endif
     ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
     const gfx::FontList& font_list =
         rb.GetFontList(ui::ResourceBundle::LargeFont);
     text_width_ = gfx::GetStringWidth(text_, font_list);
     width_ = text_width_ + kHorizontalMarginAroundText;
     height_ = font_list.GetHeight() + kVerticalMarginAroundText;
-    views::Label* label = new ExitWarningLabel;
+    views::Label* label = new views::Label();
     label->SetText(text_);
     label->SetHorizontalAlignment(gfx::ALIGN_CENTER);
     label->SetFontList(font_list);
     label->SetEnabledColor(kTextColor);
     label->SetDisabledColor(kTextColor);
     label->SetAutoColorReadabilityEnabled(false);
+    // Use a transparent background color to avoid subpixel rendering.
+    label->SetBackgroundColor(SK_ColorTRANSPARENT);

[sky, 2014/06/18 03:16:29]

Having transparent mean no subpixel rendering seems like something that could
easily change. Can we have a real API for explicitly turning off subpixel
rendering instead?

[msw, 2014/06/18 04:34:29]

AFAIK, there's no way to use subpixel rendering with a partially transparent
background, and there are many other Label users that do something similar. That
said, the background color isn't actually drawn in the general case (it's only
used for assessing readability) and I think an explicit flag is a decent idea.
I've added that alternate way to disable subpixel rendering, fixed the Textfield
usage, and updated the unit test; perhaps I'll audit and cleanup the remaining
SetBackgroundColor call sites later.

     AddChildView(label);
     SetLayoutManager(new views::FillLayout);
   }
 
   virtual gfx::Size GetPreferredSize() const OVERRIDE {
     return gfx::Size(width_, height_);
   }
 
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
     SkPaint paint;
@@ skipping 103 matching lines @@
   widget_->Show();
 
   delegate->NotifyAccessibilityEvent(ui::AX_EVENT_ALERT, true);
 }
 
 void ExitWarningHandler::Hide() {
   widget_.reset();
 }
 
 }  // namespace ash