Clean up NativeTheme (particularly CommonTheme).

ui/views/style/platform_style.cc

Index: ui/views/style/platform_style.cc
diff --git a/ui/views/style/platform_style.cc b/ui/views/style/platform_style.cc
index 39dc249c2d147d05bf3f1228724a60c5b32cda2e..a9fd9829c9d8473b82c6ad70c0c9487152b9801a 100644
--- a/ui/views/style/platform_style.cc
+++ b/ui/views/style/platform_style.cc
@@ -90,10 +90,6 @@ void PlatformStyle::ApplyLabelButtonTextStyle(
   colors[Button::STATE_HOVERED] = kStyleButtonTextColor;
   colors[Button::STATE_PRESSED] = kStyleButtonTextColor;
 
-  const ui::NativeTheme* theme = label->GetNativeTheme();
-  label->SetBackgroundColor(
-      theme->GetSystemColor(ui::NativeTheme::kColorId_ButtonBackgroundColor));
-  label->SetAutoColorReadabilityEnabled(false);

[Evan Stade, 2016/09/30 18:02:36]

afaict, the label's background color is effectively unused when the auto color
adjust is off.

Removing the auto color setting here is OK because it's repeated here:
https://cs.chromium.org/chromium/src/ui/views/controls/button/label_button.cc...

[tdanderson, 2016/09/30 21:00:56]

Acknowledged.

   label->SetShadows(gfx::ShadowValues(
       1, gfx::ShadowValue(gfx::Vector2d(0, 1), 0, kStyleButtonShadowColor)));
 }