Remove third_party/ipa_font

[yukawa]

Description

Files under third_party/ipa_font are currently used only from the rendering test for Windows.

mozc/src/base/win32/win_font_test_helper.cc

Lines 92 to 108 in ddd9730

	bool WinFontTestHelper::Initialize() {
	if (g_ipa_gothic_ == nullptr) {
	const std::string path = testing::GetSourceFileOrDie(
	{"..", "..", "..", "third_party", "ipa_font", "ipaexg.ttf"});
	g_ipa_gothic_ = LoadPrivateFont(win32::Utf8ToWide(path).c_str());
	}
	if (g_ipa_mincho_ == nullptr) {
	const std::string path = testing::GetSourceFileOrDie(
	{"..", "..", "..", "third_party", "ipa_font", "ipaexm.ttf"});
	g_ipa_mincho_ = LoadPrivateFont(win32::Utf8ToWide(path).c_str());
	}
	if (g_ipa_gothic_ == nullptr || g_ipa_mincho_ == nullptr) {
	Uninitialize();
	return false;
	}
	return true;
	}

In theory, a simple font that only contains a single glyph for A should be sufficient for our use cases.

Let's create our own test font and update our tests to use it so that we can reduce our third party dependencies.

Version or commit-id

ddd9730

[hiroyuki-komatsu]

b82b8de removed third_party/ipa_font.