Adds support for headless chrome embedder mojo services

headless/lib/browser/headless_web_contents_impl.cc

 // Copyright 2015 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 "headless/lib/browser/headless_web_contents_impl.h"
 
 #include "base/bind.h"
+#include "base/json/json_writer.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"
+#include "base/strings/utf_string_conversions.h"
 #include "base/trace_event/trace_event.h"
 #include "content/public/browser/devtools_agent_host.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_delegate.h"
-#include "content/public/browser/web_contents_observer.h"
 #include "content/public/common/bindings_policy.h"
 #include "content/public/common/service_registry.h"
 #include "content/public/renderer/render_frame.h"
 #include "headless/lib/browser/headless_browser_context_impl.h"
 #include "headless/lib/browser/headless_browser_impl.h"
 #include "headless/lib/browser/headless_browser_main_parts.h"
 #include "headless/lib/browser/headless_devtools_client_impl.h"
 #include "ui/aura/window.h"
 
 namespace headless {
@@ skipping 42 matching lines @@
     HeadlessBrowserImpl* browser) {
   content::BrowserContext* context =
       HeadlessBrowserContextImpl::From(builder->browser_context_);
   content::WebContents::CreateParams create_params(context, nullptr);
   create_params.initial_size = builder->window_size_;
 
   std::unique_ptr<HeadlessWebContentsImpl> headless_web_contents =
       base::WrapUnique(new HeadlessWebContentsImpl(
           content::WebContents::Create(create_params), browser));
 
+  headless_web_contents->mojo_services_ = std::move(builder->mojo_services_);
+  headless_web_contents->mojo_bindings_ = std::move(builder->mojo_bindings_);
   headless_web_contents->InitializeScreen(parent_window, builder->window_size_);
   if (!headless_web_contents->OpenURL(builder->initial_url_))
     return nullptr;
   return headless_web_contents;
 }
 
 // static
 std::unique_ptr<HeadlessWebContentsImpl>
 HeadlessWebContentsImpl::CreateFromWebContents(
     content::WebContents* web_contents,
@@ skipping 14 matching lines @@
   contents->SetBounds(gfx::Rect(initial_size));
   content::RenderWidgetHostView* host_view =
       web_contents_->GetRenderWidgetHostView();
   if (host_view)
     host_view->SetSize(initial_size);
 }
 
 HeadlessWebContentsImpl::HeadlessWebContentsImpl(
     content::WebContents* web_contents,
     HeadlessBrowserImpl* browser)
-    : web_contents_delegate_(new HeadlessWebContentsImpl::Delegate(browser)),
+    : content::WebContentsObserver(web_contents),
+      web_contents_delegate_(new HeadlessWebContentsImpl::Delegate(browser)),
       web_contents_(web_contents),
       browser_(browser) {
   web_contents_->SetDelegate(web_contents_delegate_.get());
 }
 
 HeadlessWebContentsImpl::~HeadlessWebContentsImpl() {
   web_contents_->Close();
 }
 
+void HeadlessWebContentsImpl::RenderFrameCreated(
+    content::RenderFrameHost* render_frame_host) {
+  if (!mojo_bindings_.empty()) {
+    render_frame_host->GetRenderViewHost()->AllowBindings(
+        content::BINDINGS_POLICY_MOJO);
+  }
+
+  content::ServiceRegistry* service_registry =
+      render_frame_host->GetServiceRegistry();
+
+  for (const MojoService& service : mojo_services_) {
+    service_registry->AddService(service.service_name, service.service_factory,
+                                 browser_->BrowserMainThread());
+  }
+}
+
+void HeadlessWebContentsImpl::DocumentOnLoadCompletedInMainFrame() {
+  // Install mojo bindings by executing the bindings js.  Note this has to be
+  // done here since this is the earliest callback the browser has after the
+  // mojo module service is created at document start.
+  content::RenderFrameHost* render_frame_host = web_contents_->GetMainFrame();
+  base::ListValue module_list;
+  for (const MojoBindings& binding : mojo_bindings_) {
+    // Note RenderFrameHostImpl is unaware of headless chrome and we have to
+    // work around it's limits on when it's safe to call JS by using the
+    // ForTests version.
+    // TODO(alexclarke): Consider fixing this.
+    render_frame_host->ExecuteJavaScriptForTests(

[Charlie Reis, 2016/06/22 23:18:48]

Calling this from non-test code is illegal for security reasons.  See
https://crbug.com/507809.  Jochen's comment in the description:
"for drive-by web content, we always run the risk that the page is setup to
intercept those calls. also, it's incredible difficult to ensure that those
calls actually do what they're supposed to do."

[alex clarke (OOO till 29th), 2016/06/23 15:14:04]

I spoke to +jochen@ about this.  He suggested we add a new scheme* for headless
webcontents with mojo bindings, and we'd teach RFH::ExecuteJavaScript about that
and use it here instead of the test method.

* E.g. chrome-headless://  

I don't know how to do that yet, but in principle it sounds reasonable.

+        base::UTF8ToUTF16(binding.js_bindings));
+    module_list.AppendString(binding.mojom_name);
+  }
+  std::string json_module_list;
+  CHECK(base::JSONWriter::Write(module_list, &json_module_list));
+  render_frame_host->ExecuteJavaScriptForTests(base::UTF8ToUTF16(
+      "mojo.resolvePromisesForServices_(" + json_module_list + ");"));
+}
+
 bool HeadlessWebContentsImpl::OpenURL(const GURL& url) {
   if (!url.is_valid())
     return false;
   content::NavigationController::LoadURLParams params(url);
   params.transition_type = ui::PageTransitionFromInt(
       ui::PAGE_TRANSITION_TYPED | ui::PAGE_TRANSITION_FROM_ADDRESS_BAR);
   web_contents_->GetController().LoadURLWithParams(params);
   web_contents_->Focus();
   return true;
 }
@@ skipping 53 matching lines @@
   window_size_ = size;
   return *this;
 }
 
 HeadlessWebContents::Builder& HeadlessWebContents::Builder::SetBrowserContext(
     HeadlessBrowserContext* browser_context) {
   browser_context_ = browser_context;
   return *this;
 }
 
+HeadlessWebContents::Builder& HeadlessWebContents::Builder::AddMojoService(
+    const std::string& service_name,
+    const base::Callback<void(mojo::ScopedMessagePipeHandle)>&
+        service_factory) {
+  mojo_services_.emplace_back(service_name, service_factory);
+  return *this;
+}
+
+HeadlessWebContents::Builder& HeadlessWebContents::Builder::AddJsMojoBindings(
+    const std::string& mojom_name,
+    const std::string& js_bindings) {
+  mojo_bindings_.emplace_back(mojom_name, js_bindings);
+  return *this;
+}
+
 HeadlessWebContents* HeadlessWebContents::Builder::Build() {
   return browser_->CreateWebContents(this);
 }
 
+HeadlessWebContents::Builder::MojoService::MojoService() {}
+
+HeadlessWebContents::Builder::MojoService::MojoService(
+    const std::string& service_name,
+    const base::Callback<void(mojo::ScopedMessagePipeHandle)>& service_factory)
+    : service_name(service_name), service_factory(service_factory) {}
+
+HeadlessWebContents::Builder::MojoService::~MojoService() {}
+
+HeadlessWebContents::Builder::MojoBindings::MojoBindings() {}
+
+HeadlessWebContents::Builder::MojoBindings::MojoBindings(
+    const std::string& mojom_name,
+    const std::string& js_bindings)
+    : mojom_name(mojom_name), js_bindings(js_bindings) {}
+
+HeadlessWebContents::Builder::MojoBindings::~MojoBindings() {}
+
 }  // namespace headless