Create direct write font proxy classes and unit tests.

content/child/dwrite_font_proxy/dwrite_localized_strings_win.h

Index: content/child/dwrite_font_proxy/dwrite_localized_strings_win.h
diff --git a/content/child/dwrite_font_proxy/dwrite_localized_strings_win.h b/content/child/dwrite_font_proxy/dwrite_localized_strings_win.h
new file mode 100644
index 0000000000000000000000000000000000000000..492ca23bbfa719193b1aac7b26012922fed01d5f
--- /dev/null
+++ b/content/child/dwrite_font_proxy/dwrite_localized_strings_win.h
@@ -0,0 +1,57 @@
+// Copyright 2015 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.
+
+#ifndef CONTENT_CHILD_DWRITE_FONT_PROXY_DWRITE_LOCALIZED_STRINGS_WIN_H_
+#define CONTENT_CHILD_DWRITE_FONT_PROXY_DWRITE_LOCALIZED_STRINGS_WIN_H_
+
+#include <dwrite.h>
+#include <wrl.h>
+#include <utility>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/strings/string16.h"
+
+namespace mswr = Microsoft::WRL;

[Alexei Svitkine (slow), 2015/11/25 20:17:45]

Header files shouldn't have using declarations.

[Ilya Kulshin, 2015/12/02 02:23:02]

Done.

+
+namespace content {
+
+// Impements IDWriteLocalizedStrings, backed by a vector of string pairs.
+class DWriteLocalizedStrings
+    : public mswr::RuntimeClass<mswr::RuntimeClassFlags<mswr::ClassicCom>,
+                                IDWriteLocalizedStrings> {
+ public:

[Alexei Svitkine (slow), 2015/11/25 20:17:45]

Nit: Add an explicit default ctor.

[Ilya Kulshin, 2015/12/02 02:23:01]

Done.

+  ~DWriteLocalizedStrings();

[Alexei Svitkine (slow), 2015/11/25 20:17:45]

Shouldn't this have override() since it's a subclass?

[Ilya Kulshin, 2015/12/02 02:23:02]

Done.

+
+  // IDWriteLocalizedStrings:
+  HRESULT STDMETHODCALLTYPE FindLocaleName(const WCHAR* locale_name,
+                                           UINT32* index,
+                                           BOOL* exists) override;
+  UINT32 STDMETHODCALLTYPE GetCount() override;
+  HRESULT STDMETHODCALLTYPE GetLocaleName(UINT32 index,
+                                          WCHAR* locale_name,
+                                          UINT32 size) override;
+  HRESULT STDMETHODCALLTYPE GetLocaleNameLength(UINT32 index,
+                                                UINT32* length) override;
+  HRESULT STDMETHODCALLTYPE GetString(UINT32 index,
+                                      WCHAR* string_buffer,
+                                      UINT32 size) override;
+  HRESULT STDMETHODCALLTYPE GetStringLength(UINT32 index,
+                                            UINT32* length) override;
+
+  HRESULT STDMETHODCALLTYPE RuntimeClassInitialize(
+      std::vector<std::pair<base::string16, base::string16>>* strings);
+
+ private:
+  // List of strings. First element of each pair is the locale, and the second
+  // element is the associated value. Use a vector because the expected number
+  // of pairs is small (typically 1-2, rarely up to a few dozen?) and we need
+  // index-based access.
+  std::vector<std::pair<base::string16, base::string16>> strings_;
+
+  DISALLOW_ASSIGN(DWriteLocalizedStrings);
+};
+
+}  // namespace content
+#endif  // CONTENT_CHILD_DWRITE_FONT_PROXY_DWRITE_LOCALIZED_STRINGS_WIN_H_