pdfviewer: compile pdfviewer in gm, only if the flag is set (currently we compile pdfviewer, even if it is not used)

R=scroggo@google.com, jvanverth@google.com

Author: edisonn@google.com

Review URL: https://codereview.chromium.org/68533003

git-svn-id: http://skia.googlecode.com/svn/trunk@12249 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/utils/SkPDFRasterizer.cpp b/src/utils/SkPDFRasterizer.cpp
index 267c803..89ac401 100644
--- a/src/utils/SkPDFRasterizer.cpp
+++ b/src/utils/SkPDFRasterizer.cpp
@@ -18,7 +18,9 @@
 
 #include "SkPDFRasterizer.h"
 #include "SkColorPriv.h"
+#ifdef SK_BUILD_NATIVE_PDF_RENDERER
 #include "SkPdfRenderer.h"
+#endif  // SK_BUILD_NATIVE_PDF_RENDERER
 
 bool SkPopplerRasterizePDF(SkStream* pdf, SkBitmap* output) {
   size_t size = pdf->getLength();
@@ -73,6 +75,8 @@
   return true;
 }
 
+#ifdef SK_BUILD_NATIVE_PDF_RENDERER
 bool SkNativeRasterizePDF(SkStream* pdf, SkBitmap* output) {
     return SkPDFNativeRenderToBitmap(pdf, output);
 }
+#endif  // SK_BUILD_NATIVE_PDF_RENDERER