Start removing enum ui::ResourceBundle::FontStyle, fix MacViews font sizes

ui/base/resource/resource_bundle.h

Index: ui/base/resource/resource_bundle.h
diff --git a/ui/base/resource/resource_bundle.h b/ui/base/resource/resource_bundle.h
index 5a3cc5a4b123117341cfd7b623e9f9ac9af12591..1382aeb9350576250739ccbd15b13e5242009944 100644
--- a/ui/base/resource/resource_bundle.h
+++ b/ui/base/resource/resource_bundle.h
@@ -43,12 +43,16 @@ class ResourceHandle;
 // such as theme graphics. Every resource is loaded only once.
 class UI_BASE_EXPORT ResourceBundle {
  public:
-  // An enumeration of the various font styles used throughout Chrome.
-  // The following holds true for the font sizes:
-  // Small <= SmallBold <= Base <= Bold <= Medium <= MediumBold <= Large.
+  // Legacy font size deltas. Consider these to be magic numbers. New code
+  // should declare their own size delta constant using an identifier that
+  // imparts some semantic meaning.
+  static const int kSmallFontDelta = -1;
+  static const int kMediumFontDelta = 3;
+  static const int kLargeFontDelta = 8;
+
+  // Legacy font style mappings. TODO(tapted): Phase these out in favour of
+  // client code providing their own constant with the desired font size delta.
   enum FontStyle {
-    // NOTE: depending upon the locale, using one of the *BoldFont below
-    // may *not* actually result in a bold font.
     SmallFont,
     SmallBoldFont,
     BaseFont,
@@ -238,10 +242,19 @@ class UI_BASE_EXPORT ResourceBundle {
   // string if the message_id is not found.
   base::string16 GetLocalizedString(int message_id);
 
-  // Returns the font list for the specified style.
-  const gfx::FontList& GetFontList(FontStyle style);
+  // Returns a font list derived from the platform-specific "Base" font list.
+  // The result is always cached and exists for the lifetime of the process.
+  const gfx::FontList& GetFontListWithDelta(
+      int size_delta,
+      gfx::Font::FontStyle style = gfx::Font::NORMAL);

[tfarina, 2016/02/24 20:39:24]

is default parameters now allowed? I thought they weren't!

[tapted, 2016/02/25 00:21:11]

This has gone through all the approvals for the google C++ style guide (e.g.
https://google.github.io/styleguide/cppguide.html#Default_Arguments [and the
internal go/cppguide] both say "Default arguments are allowed on non-virtual
functions when the default is guaranteed to always have the same value.".
They're used extensively in Blink, and it has been discussed here:
https://groups.google.com/a/chromium.org/d/msg/blink-dev/wgZ2wPHrD94/0mcVcA2x...

For this method I think it's a no-brainer.

+
+  // Returns the primary font from the FontList given by GetFontListWithDelta().
+  const gfx::Font& GetFontWithDelta(
+      int size_delta,
+      gfx::Font::FontStyle style = gfx::Font::NORMAL);
 
-  // Returns the font for the specified style.
+  // Deprecated. Returns fonts using hard-coded size deltas implied by |style|.
+  const gfx::FontList& GetFontList(FontStyle style);
   const gfx::Font& GetFont(FontStyle style);
 
   // Resets and reloads the cached fonts.  This is useful when the fonts of the
@@ -341,10 +354,6 @@ class UI_BASE_EXPORT ResourceBundle {
   // Initializes the font description of default gfx::FontList.
   void InitDefaultFontList();
 
-  // Initializes all the gfx::FontList members if they haven't yet been
-  // initialized.
-  void LoadFontsIfNecessary();
-
   // Fills the |bitmap| given the data file to look in and the |resource_id|.
   // Returns false if the resource does not exist.
   //
@@ -411,17 +420,11 @@ class UI_BASE_EXPORT ResourceBundle {
 
   gfx::Image empty_image_;
 
-  // The various font lists used. Cached to avoid repeated GDI
-  // creation/destruction.
-  scoped_ptr<gfx::FontList> base_font_list_;
-  scoped_ptr<gfx::FontList> bold_font_list_;
-  scoped_ptr<gfx::FontList> small_font_list_;
-  scoped_ptr<gfx::FontList> small_bold_font_list_;
-  scoped_ptr<gfx::FontList> medium_font_list_;
-  scoped_ptr<gfx::FontList> medium_bold_font_list_;
-  scoped_ptr<gfx::FontList> large_font_list_;
-  scoped_ptr<gfx::FontList> large_bold_font_list_;
-  scoped_ptr<gfx::FontList> web_font_list_;
+  // The various font lists used, as a map from a signed size delta from the
+  // platform base font size, plus style, to the FontList. Cached to avoid
+  // repeated GDI creation/destruction and font derivation.
+  // Must be accessed only while holding |images_and_fonts_lock_|.
+  std::map<std::pair<int, gfx::Font::FontStyle>, gfx::FontList> font_cache_;
 
   base::FilePath overridden_pak_path_;