PDF Viewer - PageUp/Down don't move pdf by page size in FitToPage mode

pdf/instance.cc

Index: pdf/instance.cc
diff --git a/pdf/instance.cc b/pdf/instance.cc
index d700be8757d679f00d98f86329a649308e64bfef..c31d4b2811470c54b0f56aa82a7bf38d0f0c5bb2 100644
--- a/pdf/instance.cc
+++ b/pdf/instance.cc
@@ -509,8 +509,12 @@ bool Instance::HandleInputEvent(const pp::InputEvent& event) {
     pp::KeyboardInputEvent keyboard_event(event);
     bool no_h_scrollbar = !h_scrollbar_.get();
     uint32_t key_code = keyboard_event.GetKeyCode();
-    bool page_down = no_h_scrollbar && key_code == ui::VKEY_RIGHT;
-    bool page_up = no_h_scrollbar && key_code == ui::VKEY_LEFT;
+    // Page down is ui::VKEY_NEXT.
+    bool page_down = no_h_scrollbar &&
+                     (key_code == ui::VKEY_RIGHT || key_code == ui::VKEY_NEXT);
+    // Page up is ui::VKEY_PRIOR.
+    bool page_up = no_h_scrollbar &&
+                   (key_code == ui::VKEY_LEFT || key_code == ui::VKEY_PRIOR);
     if (zoom_mode_ == ZOOM_FIT_TO_PAGE) {
       bool has_shift =
           keyboard_event.GetModifiers() & PP_INPUTEVENT_MODIFIER_SHIFTKEY;