Printing: PDFs should only be fit to page if there is a size mismatch.

pdf/pdfium/pdfium_engine.h

Index: pdf/pdfium/pdfium_engine.h
diff --git a/pdf/pdfium/pdfium_engine.h b/pdf/pdfium/pdfium_engine.h
index 2dc65b4100f4386812e7f581957f67bb5f0c57d6..d3a9a14150316a027f9f3c727638f7d63907efbf 100644
--- a/pdf/pdfium/pdfium_engine.h
+++ b/pdf/pdfium/pdfium_engine.h
@@ -94,6 +94,7 @@ class PDFiumEngine : public PDFEngine,
   virtual bool GetPrintScaling();
   virtual int GetCopiesToPrint();
   virtual int GetDuplexType();
+  virtual bool GetPageSizeAndUniformity(pp::Size* size);
   virtual void AppendBlankPages(int num_pages);
   virtual void AppendPage(PDFEngine* engine, int index);
   virtual pp::Point GetScrollPosition();