Add binary format support to CefMessageRouter (fixes #3502)

include/wrapper/cef_message_router.h

@@ -219,6 +219,38 @@ struct CefMessageRouterConfig {
   size_t message_size_threshold;
 };
 
+///
+/// This class acts as a container for managing binary data. It retains
+/// references to the underlying backing store, ensuring it is valid as long as
+/// the CefBinaryBuffer exists. This allows efficient, zero-copy access to data
+/// received from another process.
+///
+/// This class is not designed to be thread-safe, and it is the user's
+/// responsibility to synchronize access from multiple threads to ensure data
+/// integrity.
+///
+class CefBinaryBuffer : public CefBaseRefCounted {
+ public:
+  ///
+  /// Returns the read-only pointer to the memory. Returns nullptr if
+  /// |GetSize()| returns zero. The returned pointer is only valid for the life
+  /// span of this object.
+  ///
+  virtual const void* GetData() const = 0;
+
+  ///
+  /// Returns the writable pointer to the memory. Returns nullptr if
+  /// |GetSize()| returns zero. The returned pointer is only valid for the life
+  /// span of this object.
+  ///
+  virtual void* GetData() = 0;
+
+  ///
+  /// Returns the size of the data.
+  ///
+  virtual size_t GetSize() const = 0;
+};
+
 ///
 /// Implements the browser side of query routing. The methods of this class may
 /// be called on any browser process thread unless otherwise indicated.
@@ -238,10 +270,17 @@ class CefMessageRouterBrowserSide
    public:
     ///
     /// Notify the associated JavaScript onSuccess callback that the query has
-    /// completed successfully with the specified |response|.
+    /// completed successfully with the specified string |response|.
     ///
     virtual void Success(const CefString& response) = 0;
 
+    ///
+    /// Notify the associated JavaScript onSuccess callback that the query has
+    /// completed successfully with binary data. A |data| pointer to the binary
+    /// data can be nullptr only if the |size| is 0.
+    ///
+    virtual void Success(const void* data, size_t size) = 0;
+
     ///
     /// Notify the associated JavaScript onFailure callback that the query has
     /// failed with the specified |error_code| and |error_message|.
@@ -276,6 +315,25 @@ class CefMessageRouterBrowserSide
       return false;
     }
 
+    ///
+    /// Executed when a new query is received. |query_id| uniquely identifies
+    /// the query for the life span of the router. Return true to handle the
+    /// query or false to propagate the query to other registered handlers, if
+    /// any. If no handlers return true from this method then the query will be
+    /// automatically canceled with an error code of -1 delivered to the
+    /// JavaScript onFailure callback. If this method returns true then a
+    /// Callback method must be executed either in this method or asynchronously
+    /// to complete the query.
+    ///
+    virtual bool OnQuery(CefRefPtr<CefBrowser> browser,
+                         CefRefPtr<CefFrame> frame,
+                         int64_t query_id,
+                         CefRefPtr<const CefBinaryBuffer> request,
+                         bool persistent,
+                         CefRefPtr<Callback> callback) {
+      return false;
+    }
+
     ///
     /// Executed when a query has been canceled either explicitly using the
     /// JavaScript cancel function or implicitly due to browser destruction,