linux/chromeos: Improve querying for Fontconfig defaults.

ui/gfx/font_render_params_linux_unittest.cc

Index: ui/gfx/font_render_params_linux_unittest.cc
diff --git a/ui/gfx/font_render_params_linux_unittest.cc b/ui/gfx/font_render_params_linux_unittest.cc
index 46a4fcfaac27f036693448205271b265cc92db1e..45c1b99a125bc71058d2689c30e8fb71c983f94e 100644
--- a/ui/gfx/font_render_params_linux_unittest.cc
+++ b/ui/gfx/font_render_params_linux_unittest.cc
@@ -96,8 +96,11 @@ TEST_F(FontRenderParamsTest, Default) {
       CreateFontconfigEditStanza("hintstyle", "const", "hintslight") +
       CreateFontconfigEditStanza("rgba", "const", "rgb") +
       kFontconfigMatchFooter +
-      // Add a font match for Arial; it shouldn't be used when querying for
-      // default settings: http://crbug.com/421247
+      // Add a font match for Arial; it shouldn't be used on Chrome OS but when
+      // querying for default settings: http://crbug.com/421247
+      //
+      // The match _should_ take affect on desktop Linux, though:

[msw, 2014/12/17 22:42:23]

nit: "take effect"

[Daniel Erat, 2014/12/18 00:15:46]

oh my, that's embarrassing. i know the difference between those words. thanks.
:-/

+      // http://crbug.com/442443
       kFontconfigMatchFontHeader +
       CreateFontconfigTestStanza("family", "eq", "string", "Arial") +
       CreateFontconfigEditStanza("antialias", "bool", "true") +
@@ -110,9 +113,14 @@ TEST_F(FontRenderParamsTest, Default) {
   FontRenderParams params = GetFontRenderParams(
       FontRenderParamsQuery(true), NULL);
   EXPECT_TRUE(params.antialiasing);
-  EXPECT_TRUE(params.autohinter);
   EXPECT_TRUE(params.use_bitmaps);
+#if defined(OS_CHROMEOS)
+  EXPECT_TRUE(params.autohinter);
   EXPECT_EQ(FontRenderParams::HINTING_SLIGHT, params.hinting);
+#else
+  EXPECT_FALSE(params.autohinter);
+  EXPECT_EQ(FontRenderParams::HINTING_FULL, params.hinting);
+#endif
   EXPECT_FALSE(params.subpixel_positioning);
   EXPECT_EQ(FontRenderParams::SUBPIXEL_RENDERING_RGB,
             params.subpixel_rendering);
@@ -256,11 +264,19 @@ TEST_F(FontRenderParamsTest, UseBitmaps) {
 }
 
 TEST_F(FontRenderParamsTest, ForceFullHintingWhenAntialiasingIsDisabled) {
+#if !defined(OS_CHROMEOS)
+  ASSERT_TRUE(LoadSystemFont("arial.ttf"));
+#endif
   // Load a config that disables antialiasing and hinting while requesting
   // subpixel rendering.
   ASSERT_TRUE(LoadConfigDataIntoFontconfig(temp_dir_.path(),
       std::string(kFontconfigFileHeader) +
+#if defined(OS_CHROMEOS)
       kFontconfigMatchPatternHeader +
+#else
+      // Desktop Linux performs a match instead of using the default pattern.

[msw, 2014/12/17 22:42:23]

Shouldn't Linux fall back on the default pattern if there is no font match?
(ie. shouldn't this test still pass as-is?)

[Daniel Erat, 2014/12/18 00:15:46]

that's what i was thinking at first, but i saw failures when i tried it. for
example, "antialias" was true, which i think means that fontconfig is falling
back to its built-in defaults. but now that you mentioned it and i thought about
it a bit more, i realized that the problem is probably that fontconfig matches
require there to be at least one font installed, and this test wasn't calling
LoadSystemFont() initially. now that i've added that, it passes. without these
changes.

+      kFontconfigMatchFontHeader +
+#endif
       CreateFontconfigEditStanza("antialias", "bool", "false") +
       CreateFontconfigEditStanza("hinting", "bool", "false") +
       CreateFontconfigEditStanza("hintstyle", "const", "hintnone") +