RenderTextHarfBuzz: Try fallback fonts of the Uniscribe font while shaping

ui/gfx/render_text_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/render_text.h"
 
 #include <algorithm>
 
 #include "base/format_macros.h"
 #include "base/i18n/break_iterator.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/break_list.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/font.h"
+#include "ui/gfx/platform_font_win.h"
 #include "ui/gfx/render_text_harfbuzz.h"
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #include "ui/gfx/render_text_win.h"
 #endif
 
 #if defined(OS_LINUX) && !defined(USE_OZONE)
 #include "ui/gfx/render_text_pango.h"
 #endif
 
 using base::ASCIIToUTF16;
 using base::UTF8ToUTF16;
 using base::WideToUTF16;
+using base::WideToUTF8;
 
 namespace gfx {
 
 namespace {
 
 // Various weak, LTR, RTL, and Bidi string cases with three characters each.
 const wchar_t kWeak[] =      L" . ";
 const wchar_t kLtr[] =       L"abc";
 const wchar_t kRtl[] =       L"\x5d0\x5d1\x5d2";
 #if !defined(OS_MACOSX)
@@ skipping 2276 matching lines @@
   render_text->SetText(kString);
   render_text->ApplyStyle(BOLD, true, Range(0, 3));
   render_text->SetElideBehavior(ELIDE_TAIL);
 
   render_text->SetDisplayRect(Rect(0, 0, 500, 100));
   EXPECT_EQ(kString, render_text->GetLayoutText());
   render_text->SetDisplayRect(Rect(0, 0, render_text->GetContentWidth(), 100));
   EXPECT_EQ(kString, render_text->GetLayoutText());
 }
 
+// Ensure that the fallback fonts of the Uniscribe font are tried for shaping.
+#if defined(OS_WIN)
+TEST_F(RenderTextTest, HarfBuzz_UniscribeFallback) {
+  RenderTextHarfBuzz render_text;
+  PlatformFontWin* font_win = new PlatformFontWin("Meiryo", 12);
+  // Japanese name for Meiryo. This name won't be found in the system's linked
+  // fonts, forcing RTHB to try the Uniscribe font and its fallbacks.

[msw, 2014/10/28 18:17:56]

I'm not sure this really tests that the Uniscribe font's fallbacks are tested,
have you ensured that it fails without your fix?

[ckocagil, 2014/10/29 01:07:20]

Yes, it fails without this fix.

+  font_win->font_ref_->font_name_ = WideToUTF8(L"\x30e1\x30a4\x30ea\x30aa");
+  Font font(font_win);

[msw, 2014/10/28 18:17:56]

nit: inline this in the line below?

[ckocagil, 2014/10/29 01:07:20]

"FontList font_list(Font(font_win));" gives a syntax error due to what looks
like an instance of https://en.wikipedia.org/wiki/Most_vexing_parse

Error below:

d:\gitchromium\repo\src\ui\gfx\render_text_unittest.cc(2341) : error C2664:
'void gfx::RenderText::SetFontList(const gfx::FontList &)' : cannot convert
argument 1 from 'gfx::FontList (__cdecl *)(gfx::Font)' to 'const gfx::FontList
&'
        Reason: cannot convert from 'overloaded-function' to 'const
gfx::FontList'
        No constructor could take the source type, or constructor overload
resolution was ambiguous

[Daniel Erat, 2014/10/29 01:18:10]

you can just work around this with an extra set of parentheses around the
argument, right?

[ckocagil, 2014/10/29 02:05:16]

Oh, that works! Thanks!

+  FontList font_list(font);
+
+  render_text.SetFontList(font_list);
+  // Korean character "han".
+  render_text.SetText(WideToUTF16(L"\xd55c"));
+  render_text.EnsureLayout();
+  ASSERT_EQ(1U, render_text.runs_.size());
+  EXPECT_EQ(0U, render_text.runs_[0]->CountMissingGlyphs());
+}
+#endif  // defined(OS_WIN)
+
 }  // namespace gfx