pdfviewer: fix warning in release

experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp

Index: experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp
===================================================================
--- experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp	(revision 10010)
+++ experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp	(working copy)
@@ -75,11 +75,16 @@
     FILE* file = fopen(path, "r");
     fContentLength = getFileSize(path);
     fFileContent = new unsigned char[fContentLength + 1];
-    fread(fFileContent, fContentLength, 1, file);
+    bool ok = (0 != fread(fFileContent, fContentLength, 1, file));
     fFileContent[fContentLength] = '\0';
     fclose(file);
     file = NULL;
 
+    if (!ok) {
+        // TODO(edisonn): report read error
+        return;  // Doc will have 0 pages
+    }
+
     unsigned char* eofLine = lineHome(fFileContent, fFileContent + fContentLength - 1);
     unsigned char* xrefByteOffsetLine = previousLineHome(fFileContent, eofLine);
     unsigned char* xrefstartKeywordLine = previousLineHome(fFileContent, xrefByteOffsetLine);