Remove some PdfViewer warnings.

Fix build.

git-svn-id: http://skia.googlecode.com/svn/trunk@12438 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/PdfViewer/SkPdfFont.h b/experimental/PdfViewer/SkPdfFont.h
index 4a66edf..a46e31c 100644
--- a/experimental/PdfViewer/SkPdfFont.h
+++ b/experimental/PdfViewer/SkPdfFont.h
@@ -54,7 +54,7 @@
 public:
     SkUnencodedText(const SkPdfString* obj) {
         text = (void*)obj->c_str();
-        len = obj->lenstr();
+        len = (int) obj->lenstr();
     }
 };
 
@@ -272,7 +272,7 @@
 
         unsigned long ch4 = ch;
         char utf8[10];
-        int len = SkUTF8_FromUnichar(ch4, utf8);
+        size_t len = SkUTF8_FromUnichar((SkUnichar) ch4, utf8);
 
         canvas->drawText(utf8, len, SkDoubleToScalar(0), SkDoubleToScalar(0), *paint);