Add binary format support to CefMessageRouter (fixes #3502)

include/cef_values.h

@@ -278,6 +278,13 @@ class CefBinaryValue : public virtual CefBaseRefCounted {
   /*--cef()--*/
   virtual CefRefPtr<CefBinaryValue> Copy() = 0;
 
+  ///
+  /// Returns a pointer to the beginning of the memory block.
+  /// The returned pointer is valid as long as the CefBinaryValue is alive.
+  ///
+  /*--cef()--*/
+  virtual const void* GetRawData() = 0;
+
   ///
   /// Returns the data size.
   ///