[chromecast] Enable Mojo javascript bindings for cast_shell

chromecast/renderer/cast_content_renderer_client.cc

 // Copyright 2014 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 "chromecast/renderer/cast_content_renderer_client.h"
 
 #include <stdint.h>
+#include <string>
 
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "chromecast/base/chromecast_switches.h"
 #include "chromecast/common/media/cast_media_client.h"
 #include "chromecast/crash/cast_crash_keys.h"
+#include "chromecast/renderer/cast_gin_runner.h"
 #include "chromecast/renderer/cast_media_load_deferrer.h"
 #include "chromecast/renderer/cast_render_thread_observer.h"
 #include "chromecast/renderer/key_systems_cast.h"
 #include "chromecast/renderer/media/chromecast_media_renderer_factory.h"
 #include "chromecast/renderer/media/media_caps_observer_impl.h"
 #include "components/network_hints/renderer/prescient_networking_dispatcher.h"
+#include "content/grit/content_resources.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/render_view.h"
+#include "gin/modules/module_registry.h"
+#include "gin/per_context_data.h"
+#include "gin/public/context_holder.h"
 #include "media/base/media.h"
 #include "services/shell/public/cpp/interface_provider.h"
 #include "third_party/WebKit/public/platform/WebColor.h"
 #include "third_party/WebKit/public/web/WebFrameWidget.h"
+#include "third_party/WebKit/public/web/WebKit.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "third_party/WebKit/public/web/WebSettings.h"
 #include "third_party/WebKit/public/web/WebView.h"
+#include "ui/base/resource/resource_bundle.h"
 
 #if defined(OS_ANDROID)
 #include "media/base/android/media_codec_util.h"
 #endif  // OS_ANDROID
 
 namespace chromecast {
 namespace shell {
 
 namespace {
 
@@ skipping 99 matching lines @@
     const base::Closure& closure) {
   if (!render_frame->IsHidden() || allow_hidden_media_playback_) {
     closure.Run();
     return;
   }
 
   // Lifetime is tied to |render_frame| via content::RenderFrameObserver.
   new CastMediaLoadDeferrer(render_frame, closure);
 }
 
+void CastContentRendererClient::InjectJavaScript(

[alokp, 2016/09/14 21:55:36]

This does not need to be a member function. Make it a standalone static
function. I would also rename it to ExecuteJavascript.

[jarhar, 2016/09/15 00:32:41]

Done.

[alokp, 2016/09/16 04:27:22]

You forgot to make it a non-member function.

[jarhar, 2016/09/16 20:54:22]

Done.

+    content::RenderFrame* render_frame,
+    const int resourceId) {

[alokp, 2016/09/14 21:55:36]

resourceId -> resource_id. And no need for const.

[jarhar, 2016/09/15 00:32:41]

Done.

+  const std::string& js_string = ui::ResourceBundle::GetSharedInstance()

[alokp, 2016/09/14 21:55:36]

Use the content-client API to get js-string

[jarhar, 2016/09/15 00:32:41]

GetContentClient() cannot be accessed from here because it doesn't have
CONTENT_EXPORT on it.
https://cs.chromium.org/chromium/src/content/public/common/content_client.h?q...
Is there another way that I can access the content client?

+                                     .GetRawDataResource(resourceId)
+                                     .as_string();
+  render_frame->ExecuteJavaScript(base::UTF8ToUTF16(js_string));
+}
+
+void CastContentRendererClient::RunScriptsAtDocumentStart(
+    content::RenderFrame* render_frame) {
+  v8::HandleScope handle_scope(blink::mainThreadIsolate());

[alokp, 2016/09/14 21:55:36]

Add a high-level comment on what exactly it is doing. Better yet, create a
function called EnableMojoJsBindings and call it from here.

IMPORTANT: Can this function be called multiple times for a frame? If so, we
should only be doing this once.

[jarhar, 2016/09/15 00:32:42]

MojoBindingsController appears to make the assumption that this is only called
once per frame, and there seems to be no issues. I could check to see if a given
context already has our mojo bindings to be extra careful.

+  blink::WebLocalFrame* frame = render_frame->GetWebFrame();
+  v8::Local<v8::Context> context = frame->mainWorldScriptContext();
+  gin::PerContextData* context_data = gin::PerContextData::From(context);
+  gin::ContextHolder* context_holder = context_data->context_holder();
+  cast_runner_.reset(new CastGinRunner(frame, context_holder));

[derekjchow1, 2016/09/14 21:20:13]

I don't think this variable needs to outlive this function call. You can
probably remove the member variable and use a local unique_ptr here.

[jarhar, 2016/09/15 00:32:42]

As per our conversation, I have moved it to gin::PerContextData

+  gin::Runner::Scope scoper(cast_runner_.get());
+
+  // Initialize AMD API for Mojo.
+  render_frame->EnsureMojoBuiltinsAreAvailable(context_holder->isolate(),
+                                               context);
+  gin::ModuleRegistry::InstallGlobals(context_holder->isolate(),
+                                      context->Global());
+
+  // Inject JavaScript files in the correct dependency order.
+  static const int mojoResourceIds[] = {
+      IDR_MOJO_UNICODE_JS,   IDR_MOJO_BUFFER_JS,     IDR_MOJO_CODEC_JS,

[alokp, 2016/09/14 21:55:36]

Run git-cl format to format this properly.

[jarhar, 2016/09/15 00:32:41]

Done.

+      IDR_MOJO_CONNECTOR_JS, IDR_MOJO_VALIDATOR_JS,  IDR_MOJO_ROUTER_JS,
+      IDR_MOJO_BINDINGS_JS,  IDR_MOJO_CONNECTION_JS,
+  };
+  for (size_t i = 0; i < arraysize(mojoResourceIds); i++) {
+    InjectJavaScript(render_frame, mojoResourceIds[i]);
+  }
+}
+
 }  // namespace shell
 }  // namespace chromecast