DevTools: expose session to handlers.

content/browser/devtools/protocol/security_handler.cc

Index: content/browser/devtools/protocol/security_handler.cc
diff --git a/content/browser/devtools/protocol/security_handler.cc b/content/browser/devtools/protocol/security_handler.cc
index cf214a7fc8782702fab8d8bb77bc1a9cd7b96764..6b6808e4367c2719ae13e36f62823be48c4487f1 100644
--- a/content/browser/devtools/protocol/security_handler.cc
+++ b/content/browser/devtools/protocol/security_handler.cc
@@ -6,6 +6,7 @@
 
 #include <string>
 
+#include "content/browser/devtools/devtools_session.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
@@ -56,6 +57,15 @@ void AddExplanations(
 
 }  // namespace
 
+// static
+SecurityHandler* SecurityHandler::FromAgentHost(DevToolsAgentHostImpl* host) {
+  DevToolsSession* session = DevToolsDomainHandler::GetFirstSession(host);
+  if (!session)
+    return nullptr;
+  return static_cast<SecurityHandler*>(
+      session->GetHandlerByName(Security::Metainfo::domainName));
+}
+
 SecurityHandler::SecurityHandler()
     : DevToolsDomainHandler(Security::Metainfo::domainName),
       enabled_(false),