[chromecast] Enable Mojo javascript bindings for cast_shell

chromecast/renderer/cast_gin_runner.cc

+// Copyright 2016 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_gin_runner.h"
+
+#include "content/public/renderer/render_frame.h"
+#include "gin/per_context_data.h"
+#include "third_party/WebKit/public/web/WebFrame.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
+#include "third_party/WebKit/public/web/WebScriptSource.h"
+
+namespace chromecast {
+namespace shell {
+
+const char kCastContextData[] = "CastContextData";
+
+CastGinRunner::CastGinRunner(content::RenderFrame* render_frame,
+                             blink::WebFrame* frame,
+                             gin::ContextHolder* context_holder)
+    : content::RenderFrameObserver(render_frame),
+      frame_(frame),
+      context_holder_(context_holder) {
+  DCHECK(context_holder);
+  DCHECK(frame_);
+  v8::Isolate::Scope isolate_scope(context_holder->isolate());
+  v8::HandleScope handle_scope(context_holder->isolate());
+  // Note: this installs the runner globally. If we need to support more than
+  // one runner at a time we'll have to revisit this.
+  gin::PerContextData::From(context_holder->context())->set_runner(this);
+}
+
+void CastGinRunner::Run(const std::string& source,
+                        const std::string& resource_name) {
+  frame_->executeScript(
+      blink::WebScriptSource(blink::WebString::fromUTF8(source)));
+}
+
+v8::Local<v8::Value> CastGinRunner::Call(v8::Local<v8::Function> function,
+                                         v8::Local<v8::Value> receiver,
+                                         int argc,
+                                         v8::Local<v8::Value> argv[]) {
+  return frame_->callFunctionEvenIfScriptDisabled(function, receiver, argc,
+                                                  argv);
+}
+
+gin::ContextHolder* CastGinRunner::GetContextHolder() {
+  return context_holder_;
+}
+
+void CastGinRunner::WillReleaseScriptContext(v8::Local<v8::Context> context,
+                                             int world_id) {
+  gin::PerContextData* context_data = gin::PerContextData::From(context);
+  if (!context_data)
+    return;
+  context_data->RemoveUserData(kCastContextData);
+}
+
+void CastGinRunner::DidClearWindowObject() {
+  v8::Local<v8::Context> context =
+      render_frame()->GetWebFrame()->mainWorldScriptContext();
+  gin::PerContextData* context_data = gin::PerContextData::From(context);
+  if (!context_data)
+    return;
+  context_data->RemoveUserData(kCastContextData);
+}
+
+void CastGinRunner::OnDestruct() {
+  v8::Local<v8::Context> context =

[derekjchow1, 2016/09/16 17:02:01]

This function should call the destructor of this class, and the contents of this
function should be moved to the destructor.

See ~MojoBindingsController, which should have a similar lifetime to this class.

+      render_frame()->GetWebFrame()->mainWorldScriptContext();
+  gin::PerContextData* context_data = gin::PerContextData::From(context);
+  if (!context_data)
+    return;
+  context_data->RemoveUserData(kCastContextData);
+}
+
+}  // namespace shell
+}  // namespace chromecast