Re-land: "RenderTextWin: Break runs between any two characters that are not in the same code block"

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 263ef92d8159c7088650ddd538457e49061d7ea0..615860fddee607cb1997aad905e02b2584d20a2e 100644
--- a/ui/gfx/render_text_unittest.cc
+++ b/ui/gfx/render_text_unittest.cc
@@ -1650,5 +1650,27 @@ TEST_F(RenderTextTest, SelectionKeepsLigatures) {
     render_text->MoveCursorTo(SelectionModel(0, CURSOR_FORWARD));
   }
 }
+
+#if defined(OS_WIN)
+TEST_F(RenderTextTest, Win_BreakRunsByUnicodeBlocks) {
+  scoped_ptr<RenderTextWin> render_text(
+      static_cast<RenderTextWin*>(RenderText::CreateInstance()));
+
+  render_text->SetText(WideToUTF16(L"x\x25B6y"));
+  render_text->EnsureLayout();
+  ASSERT_EQ(3U, render_text->runs_.size());
+  EXPECT_EQ(Range(0, 1), render_text->runs_[0]->range);
+  EXPECT_EQ(Range(1, 2), render_text->runs_[1]->range);
+  EXPECT_EQ(Range(2, 3), render_text->runs_[2]->range);
+
+  render_text->SetText(WideToUTF16(L"x \x25B6 y"));
+  render_text->EnsureLayout();
+  ASSERT_EQ(3U, render_text->runs_.size());
+  EXPECT_EQ(Range(0, 2), render_text->runs_[0]->range);
+  EXPECT_EQ(Range(2, 3), render_text->runs_[1]->range);
+  EXPECT_EQ(Range(3, 5), render_text->runs_[2]->range);
+
+}
+#endif  // !defined(OS_WIN)
 
 }  // namespace gfx