Add HeadlessTabSocket

headless/public/headless_browser_context.h

Index: headless/public/headless_browser_context.h
diff --git a/headless/public/headless_browser_context.h b/headless/public/headless_browser_context.h
index 4bdd7a51d7ea8d5b7dc6aced8350c3e237fbf1d4..7f0b48ad0dcdf76c9d72386ddc89d99ba3d0c7f4 100644
--- a/headless/public/headless_browser_context.h
+++ b/headless/public/headless_browser_context.h
@@ -83,14 +83,17 @@ class HEADLESS_EXPORT HeadlessBrowserContext::Builder {
   // fetching for different network schemes.
   Builder& SetProtocolHandlers(ProtocolHandlerMap protocol_handlers);
 
-  // Specify JS mojo module bindings to be installed, one per mojom file.
-  // Note a single mojom file could potentially define many interfaces.
+  // DEPRECATED. Specify JS mojo module bindings to be installed, one per mojom
+  // file. Note a single mojom file could potentially define many interfaces.
   // |mojom_name| the name including path of the .mojom file.
   // |js_bindings| compiletime generated javascript bindings. Typically loaded
   // from gen/path/name.mojom.js.
+  // TODO(alexclarke): Remove this.
   Builder& AddJsMojoBindings(const std::string& mojom_name,
                              const std::string& js_bindings);
 
+  Builder& AddTabSocketMojoBindings();
+
   // By default if you add mojo bindings, http and https are disabled because
   // its almost certinly unsafe for arbitary sites on the internet to have
   // access to these bindings.  If you know what you're doing it may be OK to