linux/chromeos: Improve querying for Fontconfig defaults.

ui/gfx/font_render_params_linux_unittest.cc

 // Copyright 2014 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_render_params.h"
 
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/logging.h"
 #include "base/macros.h"
@@ skipping 78 matching lines @@
   ASSERT_TRUE(LoadSystemFont("arial.ttf"));
   ASSERT_TRUE(LoadConfigDataIntoFontconfig(temp_dir_.path(),
       std::string(kFontconfigFileHeader) +
       kFontconfigMatchPatternHeader +
       CreateFontconfigEditStanza("antialias", "bool", "true") +
       CreateFontconfigEditStanza("autohint", "bool", "true") +
       CreateFontconfigEditStanza("hinting", "bool", "true") +
       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") +
       CreateFontconfigEditStanza("autohint", "bool", "false") +
       CreateFontconfigEditStanza("hinting", "bool", "true") +
       CreateFontconfigEditStanza("hintstyle", "const", "hintfull") +
       kFontconfigMatchFooter +
       kFontconfigFileFooter));
 
   FontRenderParams params = GetFontRenderParams(
       FontRenderParamsQuery(true), NULL);
   EXPECT_TRUE(params.antialiasing);
+  EXPECT_TRUE(params.use_bitmaps);
+#if defined(OS_CHROMEOS)
   EXPECT_TRUE(params.autohinter);
-  EXPECT_TRUE(params.use_bitmaps);
   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);
 }
 
 TEST_F(FontRenderParamsTest, Size) {
   ASSERT_TRUE(LoadSystemFont("arial.ttf"));
   ASSERT_TRUE(LoadConfigDataIntoFontconfig(temp_dir_.path(),
       std::string(kFontconfigFileHeader) +
       kFontconfigMatchPatternHeader +
@@ skipping 123 matching lines @@
   FontRenderParamsQuery query(false);
   FontRenderParams params = GetFontRenderParams(query, NULL);
   EXPECT_FALSE(params.use_bitmaps);
 
   query.pixel_size = 5;
   params = GetFontRenderParams(query, NULL);
   EXPECT_TRUE(params.use_bitmaps);
 }
 
 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") +
       CreateFontconfigEditStanza("rgba", "const", "rgb") +
       kFontconfigMatchFooter +
       kFontconfigFileFooter));
 
   // Full hinting should be forced. See the comment in GetFontRenderParams() for
   // more information.
   FontRenderParams params = GetFontRenderParams(
@@ skipping 105 matching lines @@
   EXPECT_EQ("Verdana", suggested_family);
 
   query.families.clear();
   query.families.push_back("Arial");
   suggested_family.clear();
   GetFontRenderParams(query, &suggested_family);
   EXPECT_EQ("Verdana", suggested_family);
 }
 
 }  // namespace gfx