Update Java Bridge to use its own thread in the browser process

content/browser/renderer_host/java/java_bridge_dispatcher_host.cc

 // Copyright (c) 2011 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 "content/browser/renderer_host/java/java_bridge_dispatcher_host.h"
 
 #include "base/bind.h"
-#include "content/browser/renderer_host/browser_render_process_host.h"
+#include "base/lazy_instance.h"
+#include "base/threading/thread.h"
 #include "content/browser/renderer_host/java/java_bridge_channel_host.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/common/child_process.h"
 #include "content/common/java_bridge_messages.h"
 #include "content/common/npobject_stub.h"
 #include "content/common/npobject_util.h"  // For CreateNPVariantParam()
 #include "content/public/browser/browser_thread.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebBindings.h"
 
 using content::BrowserThread;
 
+namespace {
+class JavaBridgeThread : public base::Thread {
+ public:
+  JavaBridgeThread() : base::Thread("JavaBridge") {
+    Start();
+  }
+  virtual ~JavaBridgeThread() {
+    Stop();
+  }
+};
+base::LazyInstance<JavaBridgeThread> g_background_thread =
+    LAZY_INSTANCE_INITIALIZER;
+}  // namespace
+
 JavaBridgeDispatcherHost::JavaBridgeDispatcherHost(
     RenderViewHost* render_view_host)
     : RenderViewHostObserver(render_view_host),
       is_renderer_initialized_(false) {
 }
 
 JavaBridgeDispatcherHost::~JavaBridgeDispatcherHost() {
 }
 
 void JavaBridgeDispatcherHost::AddNamedObject(const string16& name,
@@ skipping 25 matching lines @@
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(JavaBridgeDispatcherHost, msg)
     IPC_MESSAGE_HANDLER_DELAY_REPLY(JavaBridgeHostMsg_GetChannelHandle,
                                     OnGetChannelHandle)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void JavaBridgeDispatcherHost::OnGetChannelHandle(IPC::Message* reply_msg) {
-  if (RenderProcessHost::run_renderer_in_process()) {
-    // TODO(steveblock): Fix Java Bridge with in-process renderer. See
-    // http://code.google.com/p/chromium/issues/detail?id=106838
-    CHECK(false) << "Java Bridge does not support in-process renderer";
-  }
-  BrowserThread::PostTask(
-      BrowserThread::WEBKIT,
+  g_background_thread.Get().message_loop()->PostTask(
       FROM_HERE,
       base::Bind(&JavaBridgeDispatcherHost::GetChannelHandle, this, reply_msg));
 }
 
 void JavaBridgeDispatcherHost::GetChannelHandle(IPC::Message* reply_msg) {
   // The channel creates the channel handle based on the renderer ID we passed
   // to GetJavaBridgeChannelHost() and, on POSIX, the file descriptor used by
   // the underlying channel.
   JavaBridgeHostMsg_GetChannelHandle::WriteReplyParams(
       reply_msg,
       channel_->channel_handle());
   Send(reply_msg);
 }
 
 void JavaBridgeDispatcherHost::CreateNPVariantParam(NPObject* object,
                                                     NPVariant_Param* param) {
-  // The JavaBridgeChannelHost needs to be created on the WEBKIT thread, as
+  // The JavaBridgeChannelHost needs to be created on the background thread, as
   // that is where Java objects will live, and CreateNPVariantParam() needs the
   // channel to create the NPObjectStub. To avoid blocking here until the
   // channel is ready, create the NPVariant_Param by hand, then post a message
-  // to the WEBKIT thread to set up the channel and create the corresponding
+  // to the background thread to set up the channel and create the corresponding
   // NPObjectStub. Post that message before doing any IPC, to make sure that
   // the channel and object proxies are ready before responses are received
   // from the renderer.
 
   // Create an NPVariantParam suitable for serialization over IPC from our
   // NPVariant. See CreateNPVariantParam() in npobject_utils.
   param->type = NPVARIANT_PARAM_SENDER_OBJECT_ROUTING_ID;
   int route_id = JavaBridgeChannelHost::ThreadsafeGenerateRouteID();
   param->npobject_routing_id = route_id;
 
   WebKit::WebBindings::retainObject(object);
-  BrowserThread::PostTask(
-      BrowserThread::WEBKIT,
+  g_background_thread.Get().message_loop()->PostTask(
       FROM_HERE,
       base::Bind(&JavaBridgeDispatcherHost::CreateObjectStub, this, object,
                  route_id));
 }
 
 void JavaBridgeDispatcherHost::CreateObjectStub(NPObject* object,
                                                 int route_id) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT));
-
+  DCHECK_EQ(g_background_thread.Get().message_loop(), MessageLoop::current());
   if (!channel_) {
     channel_ = JavaBridgeChannelHost::GetJavaBridgeChannelHost(
         render_view_host()->process()->id(),
         BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
   }
 
+  // NPObjectStub takes a ref to the NPObject. The lifetime of the NPObjectStub
+  // is governed by that of the NPObjectProxy in the renderer, via the channel.
   // We don't need the containing window or the page URL, as we don't do
   // re-entrant sync IPC.
   new NPObjectStub(object, channel_, route_id, 0, GURL());
   // The NPObjectStub takes a reference to the NPObject. Release the ref added
   // in CreateNPVariantParam().
   WebKit::WebBindings::releaseObject(object);
 }