Make RenderTextHarfBuzz examine full font list.

ui/gfx/render_text_unittest.cc

Index: ui/gfx/render_text_unittest.cc
diff --git a/ui/gfx/render_text_unittest.cc b/ui/gfx/render_text_unittest.cc
index 1c6f902d936fb435827912df67561e1d1af51c51..e7115814759bc19c5979bb605416db0265d23d8c 100644
--- a/ui/gfx/render_text_unittest.cc
+++ b/ui/gfx/render_text_unittest.cc
@@ -2326,4 +2326,30 @@ TEST_F(RenderTextTest, StringFitsOwnWidth) {
   EXPECT_EQ(kString, render_text->GetLayoutText());
 }
 
+// TODO(derat): Figure out why this fails on Windows: http://crbug.com/427184
+#if !defined(OS_WIN)
+// Ensure that RenderText examines all of the fonts in its FontList before
+// falling back to other fonts.
+TEST_F(RenderTextTest, FontListFallback) {
+  // Double-check that the requested fonts are present.
+  FontList font_list("Arial, Symbol, 12px");
+  const std::vector<Font>& fonts = font_list.GetFonts();
+  ASSERT_EQ(2u, fonts.size());
+  ASSERT_EQ("arial",
+            base::StringToLowerASCII(fonts[0].GetActualFontNameForTesting()));
+  ASSERT_EQ("symbol",
+            base::StringToLowerASCII(fonts[1].GetActualFontNameForTesting()));
+
+  // "⊕" (CIRCLED PLUS) should be rendered with Symbol rather than falling back
+  // to some other font that's present on the system.
+  scoped_ptr<RenderText> render_text(RenderText::CreateInstance());
+  render_text->SetFontList(font_list);
+  render_text->SetText(UTF8ToUTF16("\xE2\x8A\x95"));
+  const std::vector<RenderText::FontSpan> spans =
+      render_text->GetFontSpansForTesting();
+  ASSERT_EQ(static_cast<size_t>(1), spans.size());
+  EXPECT_EQ("Symbol", spans[0].first.GetFontName());
+}
+#endif  // !defined(OS_WIN)
+
 }  // namespace gfx