Clean-up: Renames gfx::Font's methods and removes its obsolete methods.

ui/gfx/font.cc

Index: ui/gfx/font.cc
diff --git a/ui/gfx/font.cc b/ui/gfx/font.cc
index 9eea73b608aa0ed091f8f5af1c6e508417fe7e36..31f27b4f294403deebf42fff371bca7296dc0cd1 100644
--- a/ui/gfx/font.cc
+++ b/ui/gfx/font.cc
@@ -18,7 +18,7 @@ Font::Font() : platform_font_(PlatformFont::CreateDefault()) {
 Font::Font(const Font& other) : platform_font_(other.platform_font_) {
 }
 
-gfx::Font& Font::operator=(const Font& other) {
+Font& Font::operator=(const Font& other) {
   platform_font_ = other.platform_font_;
   return *this;
 }
@@ -38,11 +38,7 @@ Font::Font(const std::string& font_name, int font_size)
 Font::~Font() {
 }
 
-Font Font::DeriveFont(int size_delta) const {
-  return DeriveFont(size_delta, GetStyle());
-}
-
-Font Font::DeriveFont(int size_delta, int style) const {
+Font Font::Derive(int size_delta, int style) const {
   return platform_font_->DeriveFont(size_delta, style);
 }
 
@@ -58,14 +54,6 @@ int Font::GetCapHeight() const {
   return platform_font_->GetCapHeight();
 }
 
-int Font::GetAverageCharacterWidth() const {
-  return platform_font_->GetAverageCharacterWidth();
-}
-
-int Font::GetStringWidth(const base::string16& text) const {
-  return platform_font_->GetStringWidth(text);
-}
-
 int Font::GetExpectedTextWidth(int length) const {
   return platform_font_->GetExpectedTextWidth(length);
 }