pdfviewer: load image pain settings (like transparency), pass the page number, report failure if at least one render fails, and check that xref section starts with xref keyword.

Review URL: https://codereview.chromium.org/22465006

git-svn-id: http://skia.googlecode.com/svn/trunk@10588 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp b/experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp
index 6386f98..333b0a2 100644
--- a/experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp
+++ b/experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp
@@ -225,7 +225,12 @@
 }
 
 const unsigned char* SkNativeParsedPDF::readCrossReferenceSection(const unsigned char* xrefStart, const unsigned char* trailerEnd) {
-    const unsigned char* current = ignoreLine(xrefStart, trailerEnd);  // TODO(edisonn): verify next keyord is "xref", use nextObject here
+    SkPdfObject xref;
+    const unsigned char* current = nextObject(0, xrefStart, trailerEnd, &xref, NULL, NULL);
+
+    if (!xref.isKeyword("xref")) {
+        return trailerEnd;
+    }
 
     SkPdfObject token;
     while (current < trailerEnd) {