[DevTools] Rework DevToolsSession interaction with domain handlers.

content/browser/devtools/protocol/tethering_handler.h

Index: content/browser/devtools/protocol/tethering_handler.h
diff --git a/content/browser/devtools/protocol/tethering_handler.h b/content/browser/devtools/protocol/tethering_handler.h
index 3d57b169b34ebf01f307d182a9b81bf77817894e..85a7fc5ed619772778d7b955331a24d629af41a5 100644
--- a/content/browser/devtools/protocol/tethering_handler.h
+++ b/content/browser/devtools/protocol/tethering_handler.h
@@ -13,6 +13,7 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
+#include "content/browser/devtools/protocol/devtools_domain_handler.h"
 #include "content/browser/devtools/protocol/tethering.h"
 
 namespace net {
@@ -23,7 +24,8 @@ namespace content {
 namespace protocol {
 
 // This class implements reversed tethering handler.
-class TetheringHandler : public Tethering::Backend {
+class TetheringHandler : public DevToolsDomainHandler,
+                         public Tethering::Backend {
  public:
   using CreateServerSocketCallback =
       base::Callback<std::unique_ptr<net::ServerSocket>(std::string*)>;
@@ -32,7 +34,8 @@ class TetheringHandler : public Tethering::Backend {
                    scoped_refptr<base::SingleThreadTaskRunner> task_runner);
   ~TetheringHandler() override;
 
-  void Wire(UberDispatcher*);
+  void Wire(UberDispatcher* dispatcher) override;
+  void SetRenderFrameHost(RenderFrameHostImpl* host) override;
   Response Disable() override;
 
   void Bind(int port, std::unique_ptr<BindCallback> callback) override;