linux: simplify gfx::Font constructor logic and add CHECK()s.

app/gfx/font_gtk.cc

 // Copyright (c) 2006-2008 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 "app/gfx/font.h"
 
 #include <fontconfig/fontconfig.h>
 #include <gtk/gtk.h>
 
 #include "base/string_util.h"
 
 namespace gfx {
 
 Font* Font::default_font_ = NULL;
 
 // Find the best match font for |family_name| in the same way as Skia
-// to make sure CreateFont() successfully creates default font.
-// In Skia, it only checks the best match font.  If it failed to find,
-// SkTypeface will be NULL for that font family.  It eventually causes segfault.
-// For example, family_name = "Sans" and system may have various fonts.
-// The first font family in FcPattern will be "DejaVu Sans" but a font family
-// returned by FcFontMatch will be "VL PGothic".
-// In this case, SkTypeface for "Sans" returns NULL even if system has font
-// for "Sans" font family.
-// See FontMatch() in skia/ports/SkFontHost_fontconfig.cpp for more detail.
+// to make sure CreateFont() successfully creates a default font.  In
+// Skia, it only checks the best match font.  If it failed to find
+// one, SkTypeface will be NULL for that font family.  It eventually
+// causes a segfault.  For example, family_name = "Sans" and system
+// may have various fonts.  The first font family in FcPattern will be
+// "DejaVu Sans" but a font family returned by FcFontMatch will be "VL
+// PGothic".  In this case, SkTypeface for "Sans" returns NULL even if
+// the system has a font for "Sans" font family.  See FontMatch() in
+// skia/ports/SkFontHost_fontconfig.cpp for more detail.
 static std::wstring FindBestMatchFontFamilyName(const char* family_name) {
-    FcPattern* pattern = FcPatternCreate();
-    FcValue fcvalue;
-    fcvalue.type = FcTypeString;
-    char* family_name_copy = strdup(family_name);
-    fcvalue.u.s = reinterpret_cast<FcChar8*>(family_name_copy);
-    FcPatternAdd(pattern, FC_FAMILY, fcvalue, 0);
-    FcConfigSubstitute(0, pattern, FcMatchPattern);
-    FcDefaultSubstitute(pattern);
-    FcResult result;
-    FcPattern* match = FcFontMatch(0, pattern, &result);
-    DCHECK(match) << "Could not find font: " << family_name;
-    FcChar8* match_family;
-    FcPatternGetString(match, FC_FAMILY, 0, &match_family);
+  FcPattern* pattern = FcPatternCreate();
+  FcValue fcvalue;
+  fcvalue.type = FcTypeString;
+  char* family_name_copy = strdup(family_name);
+  fcvalue.u.s = reinterpret_cast<FcChar8*>(family_name_copy);
+  FcPatternAdd(pattern, FC_FAMILY, fcvalue, 0);
+  FcConfigSubstitute(0, pattern, FcMatchPattern);
+  FcDefaultSubstitute(pattern);
+  FcResult result;
+  FcPattern* match = FcFontMatch(0, pattern, &result);
+  DCHECK(match) << "Could not find font: " << family_name;
+  FcChar8* match_family;
+  FcPatternGetString(match, FC_FAMILY, 0, &match_family);
 
-    std::wstring font_family = UTF8ToWide(
-        reinterpret_cast<char*>(match_family));
-    FcPatternDestroy(match);
-    FcPatternDestroy(pattern);
-    free(family_name_copy);
-    return font_family;
+  std::wstring font_family = UTF8ToWide(
+      reinterpret_cast<char*>(match_family));
+  FcPatternDestroy(match);
+  FcPatternDestroy(pattern);
+  free(family_name_copy);
+  return font_family;
 }
 
 // Get the default gtk system font (name and size).
 Font::Font() {
   if (default_font_ == NULL) {
-    gtk_init(NULL, NULL);
     GtkSettings* settings = gtk_settings_get_default();
 
-    GValue value = {0};
-    g_value_init(&value, G_TYPE_STRING);
-    g_object_get_property(G_OBJECT(settings), "gtk-font-name", &value);
+    gchar* font_name = NULL;
+    g_object_get(G_OBJECT(settings),
+                 "gtk-font-name", &font_name,
+                 NULL);
 
-    // gtk-font-name may be wrapped in quotes.
-    gchar* font_name = g_strdup_value_contents(&value);
-    gchar* font_ptr = font_name;
-    if (font_ptr[0] == '\"')
-      font_ptr++;
-    if (font_ptr[strlen(font_ptr) - 1] == '\"')
-      font_ptr[strlen(font_ptr) - 1] = '\0';
+    // Temporary CHECK for helping track down
+    // http://code.google.com/p/chromium/issues/detail?id=12530
+    CHECK(font_name) << " Unable to get gtk-font-name for default font.";
 
     PangoFontDescription* desc =
-        pango_font_description_from_string(font_ptr);
+        pango_font_description_from_string(font_name);
     gint size = pango_font_description_get_size(desc);
     const char* family_name = pango_font_description_get_family(desc);
 
     // Find best match font for |family_name| to make sure we can get
-    // SkTypeface for default font.
+    // a SkTypeface for the default font.
     // TODO(agl): remove this.
     std::wstring font_family = FindBestMatchFontFamilyName(family_name);
 
     default_font_ = new Font(CreateFont(font_family, size / PANGO_SCALE));
 
     pango_font_description_free(desc);
     g_free(font_name);
-    g_value_unset(&value);
 
     DCHECK(default_font_);
   }
 
   CopyFont(*default_font_);
 }
 
 }  // namespace gfx