[DevTools] Guard DOM.setFileInputFiles under MayAffectLocalFiles

Bug: 805557
Change-Id: Ib6f37ec6e1d091ee54621cc0c5c44f1a6beab10f
Reviewed-on: https://chromium-review.googlesource.com/c/1334847Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607902}

content/browser/devtools/protocol/dom_handler.cc

@@ -12,10 +12,10 @@
 namespace content {
 namespace protocol {
 
-DOMHandler::DOMHandler()
+DOMHandler::DOMHandler(bool allow_file_access)
     : DevToolsDomainHandler(DOM::Metainfo::domainName),
-      host_(nullptr) {
-}
+      host_(nullptr),
+      allow_file_access_(allow_file_access) {}
 
 DOMHandler::~DOMHandler() {
 }
@@ -38,6 +38,8 @@ Response DOMHandler::SetFileInputFiles(
     Maybe<DOM::NodeId> node_id,
     Maybe<DOM::BackendNodeId> backend_node_id,
     Maybe<String> in_object_id) {
+  if (!allow_file_access_)
+    return Response::Error("Not allowed");
   if (host_) {
     for (size_t i = 0; i < files->length(); i++) {
 #if defined(OS_WIN)

content/browser/devtools/protocol/dom_handler.h

@@ -18,7 +18,7 @@ namespace protocol {
 class DOMHandler : public DevToolsDomainHandler,
                    public DOM::Backend {
  public:
-  DOMHandler();
+  explicit DOMHandler(bool allow_file_access);
   ~DOMHandler() override;
 
   void Wire(UberDispatcher* dispatcher) override;
@@ -34,6 +34,7 @@ class DOMHandler : public DevToolsDomainHandler,
 
  private:
   RenderFrameHostImpl* host_;
+  bool allow_file_access_;
   DISALLOW_COPY_AND_ASSIGN(DOMHandler);
 };
 

content/browser/devtools/render_frame_devtools_agent_host.cc

@@ -226,7 +226,8 @@ bool RenderFrameDevToolsAgentHost::AttachSession(DevToolsSession* session) {
   protocol::EmulationHandler* emulation_handler =
       new protocol::EmulationHandler();
   session->AddHandler(base::WrapUnique(new protocol::BrowserHandler()));
-  session->AddHandler(base::WrapUnique(new protocol::DOMHandler()));
+  session->AddHandler(base::WrapUnique(
+      new protocol::DOMHandler(session->client()->MayAffectLocalFiles())));
   session->AddHandler(base::WrapUnique(emulation_handler));
   session->AddHandler(base::WrapUnique(new protocol::InputHandler()));
   session->AddHandler(base::WrapUnique(new protocol::InspectorHandler()));