Another round of PDF plugin cleanups.

pdf/pdfium/pdfium_range.cc

Index: pdf/pdfium/pdfium_range.cc
diff --git a/pdf/pdfium/pdfium_range.cc b/pdf/pdfium/pdfium_range.cc
index b0474fc7d679351c70ce25cf6d068264d061b4ce..3b8371f7f6ce3b2127e94231d52fade6d2a022b3 100644
--- a/pdf/pdfium/pdfium_range.cc
+++ b/pdf/pdfium/pdfium_range.cc
@@ -57,7 +57,7 @@ std::vector<pp::Rect> PDFiumRange::GetScreenRects(const pp::Point& offset,
   return cached_screen_rects_;
 }
 
-base::string16 PDFiumRange::GetText() {
+base::string16 PDFiumRange::GetText() const {
   int index = char_index_;
   int count = char_count_;
   base::string16 rv;