Add NaCl support to app_shell

extensions/shell/browser/shell_browser_pepper_host_factory.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 "extensions/shell/browser/shell_browser_pepper_host_factory.h"
+
+#include "content/public/browser/browser_ppapi_host.h"
+#include "content/public/browser/browser_thread.h"
+#include "ppapi/host/dispatch_host_message.h"
+#include "ppapi/host/message_filter_host.h"
+#include "ppapi/host/ppapi_host.h"
+#include "ppapi/host/resource_host.h"
+#include "ppapi/host/resource_message_filter.h"
+#include "ppapi/proxy/ppapi_messages.h"
+#include "ppapi/shared_impl/ppapi_permissions.h"
+
+using content::BrowserPpapiHost;
+using content::BrowserThread;
+using ppapi::host::HostMessageContext;
+using ppapi::host::MessageFilterHost;
+using ppapi::host::ResourceHost;
+using ppapi::host::ResourceMessageFilter;
+
+namespace extensions {
+namespace {
+
+// This filter handles messages for the PepperBrokerHost on the UI thread.
+class PepperBrokerMessageFilter : public ResourceMessageFilter {
+ public:
+  PepperBrokerMessageFilter() {}
+
+ private:
+  // Class is ref-counted.
+  virtual ~PepperBrokerMessageFilter() {}
+
+  // ppapi::host::ResourceMessageFilter overrides.
+  virtual scoped_refptr<base::TaskRunner> OverrideTaskRunnerForMessage(
+      const IPC::Message& message) OVERRIDE {
+    return BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI);
+  }
+
+  virtual int32_t OnResourceMessageReceived(
+      const IPC::Message& msg,
+      HostMessageContext* context) OVERRIDE {
+    PPAPI_BEGIN_MESSAGE_MAP(PepperBrokerMessageFilter, msg)
+      PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(PpapiHostMsg_Broker_IsAllowed,
+                                          OnIsAllowed)
+    PPAPI_END_MESSAGE_MAP()
+    return PP_ERROR_FAILED;
+  }
+
+  int32_t OnIsAllowed(HostMessageContext* context) {
+    // app_shell always allows access to private APIs.

[teravest, 2014/08/12 15:48:31]

I don't understand this comment.

PpapiHostMsg_Broker_IsAllowed is sent to determine if a plugin can connect to
the broker to perform some operations. 

The Pepper Broker is for supporting unsandboxed plugins (like flash)-- I don't
think you should need it to support NaCl plugins, and you should consider
splitting any Broker stuff out to another change if you need it.

If you don't have to deal with the pepper broker, I don't think you need this
message filter at all.

[James Cook, 2014/08/12 18:17:06]

Yeah, I don't need this at all.  Removed.

+    return PP_OK;
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(PepperBrokerMessageFilter);
+};
+
+}  // namespace
+
+ShellBrowserPepperHostFactory::ShellBrowserPepperHostFactory(
+    content::BrowserPpapiHost* host)
+    : host_(host) {
+}
+
+ShellBrowserPepperHostFactory::~ShellBrowserPepperHostFactory() {}
+
+scoped_ptr<ResourceHost> ShellBrowserPepperHostFactory::CreateResourceHost(
+    ppapi::host::PpapiHost* host,
+    const ppapi::proxy::ResourceMessageCallParams& params,
+    PP_Instance instance,
+    const IPC::Message& message) {
+  DCHECK(host == host_->GetPpapiHost());
+
+  // Make sure the plugin is giving us a valid instance for this resource.
+  if (!host_->IsValidInstance(instance))
+    return scoped_ptr<ResourceHost>();
+
+  // Private interfaces.
+  if (host_->GetPpapiHost()->permissions().HasPermission(
+          ppapi::PERMISSION_PRIVATE)) {
+    switch (message.type()) {
+      case PpapiHostMsg_Broker_Create::ID: {
+        scoped_refptr<ResourceMessageFilter> broker_filter(
+            new PepperBrokerMessageFilter);
+        return scoped_ptr<ResourceHost>(
+            new MessageFilterHost(host_->GetPpapiHost(),
+                                  instance,
+                                  params.pp_resource(),
+                                  broker_filter));
+      }
+    }
+  }
+
+  // app_shell does not support the custom messages for:
+  // * Flash
+  // * Android Runtime for Chrome
+  // * Content protected output
+  // * Platform verification
+  // See ChromeBrowserPepperHostFactory for how Chrome handles those.
+  return scoped_ptr<ResourceHost>();
+}
+
+}  // namespace extensions