Fix CJK font linking size on Windows XP.

ui/gfx/platform_font_win_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/platform_font_win.h"
+
+#include "base/logging.h"
+#include "base/memory/ref_counted.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gfx/font.h"
+
+namespace gfx {
+
+namespace {
+
+// Returns a font based on |base_font| with height at most |target_height| and
+// font size maximized. Returns |base_font| if height is already equal.
+gfx::Font AdjustFontSizeForHeight(const gfx::Font& base_font,
+                                  int target_height) {
+  Font expected_font = base_font;
+  if (base_font.GetHeight() < target_height) {
+    // Increase size while height is <= |target_height|.
+    Font larger_font = base_font.DeriveFont(1, 0);
+    while (larger_font.GetHeight() <= target_height) {
+      expected_font = larger_font;
+      larger_font = larger_font.DeriveFont(1, 0);
+    }
+  } else if (expected_font.GetHeight() > target_height) {
+    // Decrease size until height is <= |target_height|.
+    do {
+      expected_font = expected_font.DeriveFont(-1, 0);
+    } while (expected_font.GetHeight() > target_height);
+  }
+  return expected_font;
+}
+
+}  // namespace
+
+TEST(PlatformFontWinTest, DeriveFontWithHeight_SameHeight) {
+  const Font font;
+  PlatformFontWin* platform_font =
+      static_cast<PlatformFontWin*>(font.platform_font());
+
+  Font derived_font =
+      platform_font->DeriveFontWithHeight(font.GetHeight(), font.GetStyle());
+  EXPECT_EQ(font.GetHeight(), derived_font.GetHeight());
+  EXPECT_EQ(font.GetStyle(), derived_font.GetStyle());
+
+  derived_font = platform_font->DeriveFontWithHeight(font.GetHeight(),
+                                                     Font::BOLD);
+  EXPECT_EQ(font.GetHeight(), derived_font.GetHeight());
+  EXPECT_EQ(Font::BOLD, derived_font.GetStyle());
+}
+
+TEST(PlatformFontWinTest, DeriveFontWithHeight) {

[msw, 2012/04/26 22:14:13]

Awesome, and now this covers the case of DeriveFontWithHeight_SameHeight? You
can probably remove that test.

[Alexei Svitkine (slow), 2012/04/26 22:22:29]

Good point.

[Alexei Svitkine (slow), 2012/04/27 15:15:27]

Done.

+  const Font base_font;
+  PlatformFontWin* platform_font =
+      static_cast<PlatformFontWin*>(base_font.platform_font());
+
+  for (int i = -10; i < 10; i++) {
+    const int target_height = base_font.GetHeight() + i;
+    Font expected_font = AdjustFontSizeForHeight(base_font, target_height);
+    ASSERT_LE(expected_font.GetHeight(), target_height);
+
+    Font derived_font = platform_font->DeriveFontWithHeight(target_height, 0);
+    EXPECT_EQ(expected_font.GetFontSize(), derived_font.GetFontSize());
+    EXPECT_LE(expected_font.GetHeight(), target_height);
+    EXPECT_EQ(0, derived_font.GetStyle());
+
+    derived_font = platform_font->DeriveFontWithHeight(target_height,
+                                                       Font::BOLD);
+    EXPECT_EQ(expected_font.GetFontSize(), derived_font.GetFontSize());
+    EXPECT_LE(expected_font.GetHeight(), target_height);
+    EXPECT_EQ(Font::BOLD, derived_font.GetStyle());
+  }
+}
+
+}  // namespace gfx