Handle long press in PDF documents.

pdf/pdf_engine.h

Index: pdf/pdf_engine.h
diff --git a/pdf/pdf_engine.h b/pdf/pdf_engine.h
index 2688f25a4943cae92f2449331ab0d8df8d99809e..8410aaf318d4861ccaa45705df8db9ac54d5c7bd 100644
--- a/pdf/pdf_engine.h
+++ b/pdf/pdf_engine.h
@@ -142,6 +142,9 @@ class PDFEngine {
     // Calls the client's OnCallback() function in delay_in_ms with the given
     // id.
     virtual void ScheduleCallback(int id, int delay_in_ms) = 0;
+    // Calls the client's OnTouchTimerCallback() function in delay_in_ms with
+    // the given id.
+    virtual void ScheduleTouchTimerCallback(int id, int delay_in_ms) = 0;
 
     // Searches the given string for "term" and returns the results.  Unicode-
     // aware.
@@ -250,6 +253,8 @@ class PDFEngine {
   virtual void SetGrayscale(bool grayscale) = 0;
   // Callback for timer that's set with ScheduleCallback().
   virtual void OnCallback(int id) = 0;
+  // Callback for timer that's set with ScheduleTouchTimerCallback().
+  virtual void OnTouchTimerCallback(int id) = 0;
   // Get the number of characters on a given page.
   virtual int GetCharCount(int page_index) = 0;
   // Get the bounds in page pixels of a character on a given page.