Use #if instead of #ifdef with SK_HAS_DWRITE_X.

Review URL: https://codereview.chromium.org/943233004
diff --git a/src/ports/SkFontMgr_win_dw.cpp b/src/ports/SkFontMgr_win_dw.cpp
index 669a95b..bff8593 100644
--- a/src/ports/SkFontMgr_win_dw.cpp
+++ b/src/ports/SkFontMgr_win_dw.cpp
@@ -266,7 +266,7 @@
         , fFontCollection(SkRefComPtr(fontCollection))
         , fLocaleName(localeNameLength)
     {
-#ifdef SK_HAS_DWRITE_2_H
+#if SK_HAS_DWRITE_2_H
         if (!SUCCEEDED(fFactory->QueryInterface(&fFactory2))) {
             // IUnknown::QueryInterface states that if it fails, punk will be set to NULL.
             // http://blogs.msdn.com/b/oldnewthing/archive/2004/03/26/96777.aspx
@@ -304,7 +304,7 @@
                                              IDWriteFontFamily* fontFamily) const;
 
     SkTScopedComPtr<IDWriteFactory> fFactory;
-#ifdef SK_HAS_DWRITE_2_H
+#if SK_HAS_DWRITE_2_H
     SkTScopedComPtr<IDWriteFactory2> fFactory2;
 #endif
     SkTScopedComPtr<IDWriteFontCollection> fFontCollection;