pdf viewer: fix a few warnings, and enable warning as errors

Review URL: https://codereview.chromium.org/18293012

git-svn-id: http://skia.googlecode.com/svn/trunk@9966 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp b/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp
index dd72acd..4e2f558 100644
--- a/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp
+++ b/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp
@@ -700,7 +700,9 @@
     // free the unparsed stream, we don't need it.
     // the parsed one is locked as it contains the strings and keywords referenced in objects
     if (fUncompressedStream) {
-        realloc(fUncompressedStreamStart, fUncompressedStream - fUncompressedStreamStart);
+        void* dummy = realloc(fUncompressedStreamStart, fUncompressedStream - fUncompressedStreamStart);
+        SkASSERT(dummy == fUncompressedStreamStart);
+        fUncompressedStreamStart = (unsigned char*)dummy;  // suporess compiler warning
     } else {
         SkASSERT(false);
     }