Clean-up: Replaces obsolete Font/FontList methods.

ash/system/session_length_limit/tray_session_length_limit.cc

Index: ash/system/session_length_limit/tray_session_length_limit.cc
diff --git a/ash/system/session_length_limit/tray_session_length_limit.cc b/ash/system/session_length_limit/tray_session_length_limit.cc
index 490b7431ef81df94db157a1fca862f26e98e2330..3d8009635870533a5b04e85bc8c32c6b059abc69 100644
--- a/ash/system/session_length_limit/tray_session_length_limit.cc
+++ b/ash/system/session_length_limit/tray_session_length_limit.cc
@@ -54,8 +54,8 @@ views::Label* CreateAndSetupLabel() {
   views::Label* label = new views::Label;
   label->SetHorizontalAlignment(gfx::ALIGN_LEFT);
   SetupLabelForTray(label);
-  label->SetFontList(label->font_list().DeriveFontListWithSizeDeltaAndStyle(
-      0, label->font_list().GetFontStyle() & ~gfx::Font::BOLD));
+  label->SetFontList(label->font_list().DeriveWithStyle(
+      label->font_list().GetFontStyle() & ~gfx::Font::BOLD));
   return label;
 }