SkPDF: allow PDF module to be disabled in DM and SampleApp

tests/AnnotationTest.cpp

Index: tests/AnnotationTest.cpp
diff --git a/tests/AnnotationTest.cpp b/tests/AnnotationTest.cpp
index 7a1ca97a5543471bdef74c97541c250fb3ec7c45..a40a5f427b68471876f7e8f5d2d948f8d33e755d 100644
--- a/tests/AnnotationTest.cpp
+++ b/tests/AnnotationTest.cpp
@@ -12,6 +12,8 @@
 #include "SkStream.h"
 #include "Test.h"
 
+#if SK_SUPPORT_PDF
+
 /** Returns true if data (may contain null characters) contains needle (null
  *  terminated). */
 static bool ContainsString(const char* data, size_t dataSize, const char* needle) {
@@ -74,3 +76,4 @@ DEF_TEST(Annotation_NamedDestination, reporter) {
     REPORTER_ASSERT(reporter,
         ContainsString(rawOutput, out->size(), "/example "));
 }
+#endif  // SK_SUPPORT_PDF