Remove the unused parts of PPB_PDF

components/pdf/browser/pdf_web_contents_helper_client.h

Index: components/pdf/browser/pdf_web_contents_helper_client.h
diff --git a/components/pdf/browser/pdf_web_contents_helper_client.h b/components/pdf/browser/pdf_web_contents_helper_client.h
index 17dfb4ea06c770c87bb41dcb52d8157be860b3ff..71743c73755fb9b154b75237bd6be84681c842ea 100644
--- a/components/pdf/browser/pdf_web_contents_helper_client.h
+++ b/components/pdf/browser/pdf_web_contents_helper_client.h
@@ -31,11 +31,6 @@ class PDFWebContentsHelperClient {
   virtual void OnPDFHasUnsupportedFeature(content::WebContents* contents) = 0;
 
   virtual void OnSaveURL(content::WebContents* contents) = 0;
-
-  virtual void OnShowPDFPasswordDialog(
-      content::WebContents* contents,
-      const base::string16& prompt,
-      const PasswordDialogClosedCallback& callback) = 0;
 };
 
 }  // namespace pdf