DevTools protocol interception, blocking & modification of requests

content/browser/devtools/render_frame_devtools_agent_host.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/devtools/render_frame_devtools_agent_host.h"
 
 #include <tuple>
 #include <utility>
 
 #include "base/guid.h"
@@ skipping 407 matching lines @@
 bool RenderFrameDevToolsAgentHost::IsNetworkHandlerEnabled(
     FrameTreeNode* frame_tree_node) {
   RenderFrameDevToolsAgentHost* agent_host = GetAgentHostFor(frame_tree_node);
   if (!agent_host || !agent_host->session())
     return false;
   return protocol::NetworkHandler::FromSession(agent_host->session())
       ->enabled();
 }
 
 // static
-std::string RenderFrameDevToolsAgentHost::UserAgentOverride(
-    FrameTreeNode* frame_tree_node) {
+void RenderFrameDevToolsAgentHost::ModifyRequestHeadersIfNeeded(
+    FrameTreeNode* frame_tree_node,
+    net::HttpRequestHeaders* headers) {
   RenderFrameDevToolsAgentHost* agent_host = GetAgentHostFor(frame_tree_node);
   if (!agent_host || !agent_host->session())
-    return std::string();
-  return protocol::NetworkHandler::FromSession(agent_host->session())
-      ->UserAgentOverride();
+    return;
+  protocol::NetworkHandler* network_handler =
+      protocol::NetworkHandler::FromSession(agent_host->session());
+  std::string user_agent_override = network_handler->UserAgentOverride();
+  if (!user_agent_override.empty()) {
+    headers->SetHeader(net::HttpRequestHeaders::kUserAgent,
+                       user_agent_override);
+  }
+  if (network_handler->interception_enabled()) {
+    // Needed by DevToolsURLRequestInterceptor and will be removed by
+    // DevToolsNetworkTransaction::Start before the request is actually sent.
+    headers->SetHeader("X-DevTools-Emulate-Network-Conditions-Client-Id",
+                       agent_host->GetId());
+  }
 }
 
 // static
 void RenderFrameDevToolsAgentHost::WebContentsCreated(
     WebContents* web_contents) {
   if (ShouldForceCreation()) {
     // Force agent host.
     DevToolsAgentHost::GetOrCreateFor(web_contents);
   }
 }
@@ skipping 733 matching lines @@
     RenderFrameHost* host) {
   return (current_ && current_->host() == host) ||
       (pending_ && pending_->host() == host);
 }
 
 bool RenderFrameDevToolsAgentHost::IsChildFrame() {
   return current_ && current_->host()->GetParent();
 }
 
 }  // namespace content