Remove Label::PaintText overrides.

ash/accelerators/exit_warning_handler.cc

Index: ash/accelerators/exit_warning_handler.cc
diff --git a/ash/accelerators/exit_warning_handler.cc b/ash/accelerators/exit_warning_handler.cc
index d2dc0f56a6266b6f8f81f03a6c876e9d829570bd..2be12b081f158f7f03ead98967a8a029ef6d6d03 100644
--- a/ash/accelerators/exit_warning_handler.cc
+++ b/ash/accelerators/exit_warning_handler.cc
@@ -38,27 +38,6 @@ 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) {
@@ -77,13 +56,15 @@ class ExitWarningWidgetDelegateView : public views::WidgetDelegateView {
     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);
   }