Relanding this with font test fixes for gdi.

ui/gfx/font_list_unittest.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 <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 248 matching lines @@
 TEST(FontListTest, Fonts_GetHeight_GetBaseline) {
   // If a font list has only one font, the height and baseline must be the same.
   Font font1("Arial", 16);
   ASSERT_EQ("arial",
             base::StringToLowerASCII(font1.GetActualFontNameForTesting()));
   FontList font_list1("Arial, 16px");
   EXPECT_EQ(font1.GetHeight(), font_list1.GetHeight());
   EXPECT_EQ(font1.GetBaseline(), font_list1.GetBaseline());
 
   // If there are two different fonts, the font list returns the max value
-  // for ascent and descent.
+  // for the baseline (ascent) and height.

[msw, 2015/01/13 22:43:59]

nit: revert this comment for the height, it's actually the descent.

   Font font2("Symbol", 16);
   ASSERT_EQ("symbol",
             base::StringToLowerASCII(font2.GetActualFontNameForTesting()));
   EXPECT_NE(font1.GetBaseline(), font2.GetBaseline());
-  EXPECT_NE(font1.GetHeight() - font1.GetBaseline(),
-            font2.GetHeight() - font2.GetBaseline());
+  EXPECT_NE(font1.GetHeight(), font2.GetHeight());

[msw, 2015/01/13 21:59:57]

nit: can you leave this check as it was?

[ananta, 2015/01/13 22:21:46]

No. This check fails on DW and also fails with GDI for font heights like 55. 

[msw, 2015/01/13 22:43:59]

That's unfortunate, the test loses value if we can't ensure that the fontlist
descent is actually the maximum of its distinct constituent font descents.
Perhaps and a TODO comment: "// TODO: Find a size and font pair with reliably
distinct descents."

[ananta, 2015/01/13 23:39:40]

Added a TODO

   std::vector<Font> fonts;
   fonts.push_back(font1);
   fonts.push_back(font2);
   FontList font_list_mix(fonts);
   // ascent of FontList == max(ascent of Fonts)
+  EXPECT_EQ(std::max(font1.GetBaseline(), font2.GetBaseline()),
+            font_list_mix.GetBaseline());
+  // descent of FontList == max(descent of Fonts)
   EXPECT_EQ(std::max(font1.GetHeight() - font1.GetBaseline(),
                      font2.GetHeight() - font2.GetBaseline()),
             font_list_mix.GetHeight() - font_list_mix.GetBaseline());
-  // descent of FontList == max(descent of Fonts)
-  EXPECT_EQ(std::max(font1.GetBaseline(), font2.GetBaseline()),
-            font_list_mix.GetBaseline());
 }
 
 TEST(FontListTest, Fonts_DeriveWithHeightUpperBound) {
   std::vector<Font> fonts;
 
   fonts.push_back(gfx::Font("Arial", 18));
   fonts.push_back(gfx::Font("Sans serif", 18));
   fonts.push_back(gfx::Font("Symbol", 18));
   FontList font_list = FontList(fonts);
 
   // A smaller upper bound should derive a font list with a smaller height.
   const int height_1 = font_list.GetHeight() - 5;
   FontList derived_1 = font_list.DeriveWithHeightUpperBound(height_1);
   EXPECT_LE(derived_1.GetHeight(), height_1);
   EXPECT_LT(derived_1.GetHeight(), font_list.GetHeight());
   EXPECT_LT(derived_1.GetFontSize(), font_list.GetFontSize());
 
   // A larger upper bound should not change the height of the font list.
   const int height_2 = font_list.GetHeight() + 5;
   FontList derived_2 = font_list.DeriveWithHeightUpperBound(height_2);
   EXPECT_LE(derived_2.GetHeight(), height_2);
   EXPECT_EQ(font_list.GetHeight(), derived_2.GetHeight());
   EXPECT_EQ(font_list.GetFontSize(), derived_2.GetFontSize());
 }
 
 }  // namespace gfx