Update PDF accessibility when zoom level changes

pdf/out_of_process_instance.h

Index: pdf/out_of_process_instance.h
diff --git a/pdf/out_of_process_instance.h b/pdf/out_of_process_instance.h
index c30024824c07cbdea622eee05e32f06bbd77b3f7..a998537dfd1e27548cf580d50715c68c928afb51 100644
--- a/pdf/out_of_process_instance.h
+++ b/pdf/out_of_process_instance.h
@@ -79,12 +79,6 @@ class OutOfProcessInstance : public pp::Instance,
   void GetPrintPresetOptionsFromDocument(PP_PdfPrintPresetOptions_Dev* options);
   void EnableAccessibility();
 
-  // Start loading accessibility information.
-  void LoadAccessibility();
-
-  // Send accessibility information about the given page index.
-  void SendNextAccessibilityPage(int32_t page_index);
-
   void FlushCallback(int32_t result);
   void DidOpen(int32_t result);
   void DidOpenPreview(int32_t result);
@@ -182,6 +176,17 @@ class OutOfProcessInstance : public pp::Instance,
 
   void UserMetricsRecordAction(const std::string& action);
 
+  // Start loading accessibility information.
+  void LoadAccessibility();
+
+  // Send accessibility information about the given page index.
+  void SendNextAccessibilityPage(int32_t page_index);
+
+  // Send the accessibility information about the current viewport. This is
+  // done once when accessibility is first loaded and again when the geometry
+  // changes.
+  void SendAccessibilityViewportInfo();
+
   enum DocumentLoadState {
     LOAD_STATE_LOADING,
     LOAD_STATE_COMPLETE,