RenderTextMac: Fix crash when passed an invalid font.

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 a5656060bebbd45d4076046fc5bf9fbc43b397b9..84daa1492b5ec9760424c402642ec88094b21f33 100644
--- a/ui/gfx/render_text_unittest.cc
+++ b/ui/gfx/render_text_unittest.cc
@@ -4349,6 +4349,22 @@ TEST_P(RenderTextHarfBuzzTest, GetSubstringBoundsMultiline) {
   EXPECT_EQ(expected_total_bounds, GetSelectionBoundsUnion());
 }
 
+// Tests that RenderText doesn't crash even if it's passed an invalid font.
+TEST_P(RenderTextTest, InvalidFont) {
+// TODO(crbug.com/) This crashes with RenderTextHarfBuzz on Mac.
+#if defined(OS_MACOSX)
+  if (GetParam() == RENDER_TEXT_HARFBUZZ)
+    return;
+#endif
+  const std::string font_name = "invalid_font";
+  const int kFontSize = 13;
+  RenderText* render_text = GetRenderText();
+  render_text->SetFontList(FontList(Font(font_name, kFontSize)));
+  render_text->SetText(ASCIIToUTF16("hello"));
+
+  DrawVisualText();
+}
+
 // Prefix for test instantiations intentionally left blank since each test
 // fixture class has a single parameterization.
 #if defined(OS_MACOSX)