[DevTools] Rework DevToolsSession interaction with domain handlers.

content/browser/devtools/protocol/network_handler.cc

Index: content/browser/devtools/protocol/network_handler.cc
diff --git a/content/browser/devtools/protocol/network_handler.cc b/content/browser/devtools/protocol/network_handler.cc
index 1aa8efca1aa34cbb4e5119f930ae81ec1e940e84..60f76e22fe0c94fb9ed50cba64e1b9c8ff5fdeae 100644
--- a/content/browser/devtools/protocol/network_handler.cc
+++ b/content/browser/devtools/protocol/network_handler.cc
@@ -9,6 +9,7 @@
 #include "base/containers/hash_tables.h"
 #include "base/strings/stringprintf.h"
 #include "base/time/time.h"
+#include "content/browser/devtools/devtools_session.h"
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
 #include "content/public/browser/browser_context.h"
@@ -267,12 +268,20 @@ class GetAllCookiesCommand
 }  // namespace
 
 NetworkHandler::NetworkHandler()
-    : host_(nullptr), enabled_(false) {
+    : DevToolsDomainHandler(Network::Metainfo::domainName),
+      host_(nullptr),
+      enabled_(false) {
 }
 
 NetworkHandler::~NetworkHandler() {
 }
 
+// static
+NetworkHandler* NetworkHandler::FromSession(DevToolsSession* session) {
+  return static_cast<NetworkHandler*>(
+      session->GetHandlerByName(Network::Metainfo::domainName));
+}
+
 void NetworkHandler::Wire(UberDispatcher* dispatcher) {
   Network::Dispatcher::wire(dispatcher, this);
 }