[Win, Linux] Always display the avatar button text at the same size.

ui/gfx/font_list.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/font_list.h"
 
 #include "base/lazy_instance.h"
 #include "base/strings/string_util.h"
 #include "ui/gfx/font_list_impl.h"
 
@@ skipping 88 matching lines @@
 }
 
 const std::vector<Font>& FontList::GetFonts() const {
   return impl_->GetFonts();
 }
 
 const Font& FontList::GetPrimaryFont() const {
   return impl_->GetPrimaryFont();
 }
 
+gfx::FontList FontList::GetLargestFontListWithHeightBound(int height) const {
+  gfx::FontList font_list(*this);
+  for (int font_size = font_list.GetFontSize(); font_size > 1; --font_size) {
+    const int internal_leading =
+        font_list.GetBaseline() - font_list.GetCapHeight();
+    // Some platforms don't support getting the cap height, and simply return
+    // the entire font ascent from GetCapHeight().  Centering the ascent makes
+    // the font look too low, so if GetCapHeight() returns the ascent, center
+    // the entire font height instead.
+    const int space =
+        height - ((internal_leading != 0) ?
+                  font_list.GetCapHeight() : font_list.GetHeight());
+    const int y_offset = space / 2 - internal_leading;
+    const int space_at_bottom = height - (y_offset + font_list.GetHeight());
+    if ((y_offset >= 0) && (space_at_bottom >= 0))
+      break;
+    font_list = font_list.DeriveWithSizeDelta(-1);
+  }
+  return font_list;
+}
+
 FontList::FontList(FontListImpl* impl) : impl_(impl) {}
 
 // static
 const scoped_refptr<FontListImpl>& FontList::GetDefaultImpl() {
   // SetDefaultFontDescription() must be called and the default font description
   // must be set earlier than any call of this function.
   DCHECK(!(g_default_font_description == NULL))  // != is not overloaded.
       << "SetDefaultFontDescription has not been called.";
 
   if (!g_default_impl_initialized) {
     g_default_impl.Get() =
         g_default_font_description.Get().empty() ?
             new FontListImpl(Font()) :
             new FontListImpl(g_default_font_description.Get());
     g_default_impl_initialized = true;
   }
 
   return g_default_impl.Get();
 }
 
 }  // namespace gfx