Have mojo_shell run in its custom thread on android.

mojo/shell/ui_service_loader_android.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 "mojo/shell/ui_service_loader_android.h"
+
+#include "base/bind.h"
+#include "mojo/service_manager/service_manager.h"
+#include "mojo/shell/context.h"
+
+namespace mojo {
+
+class UIServiceLoader::UILoader {
+ public:
+  explicit UILoader(ServiceLoader* loader) : loader_(loader) {}
+  ~UILoader() {}
+
+  void LoadService(ServiceManager* manager,
+                   const GURL& url,
+                   ScopedMessagePipeHandle shell_handle) {
+    loader_->LoadService(manager, url, shell_handle.Pass());
+  }
+
+  void OnServiceError(ServiceManager* manager, const GURL& url) {
+    loader_->OnServiceError(manager, url);
+  }
+
+ private:
+  ServiceLoader* loader_;  // Owned by UIServiceLoader
+
+  DISALLOW_COPY_AND_ASSIGN(UILoader);
+};
+
+UIServiceLoader::UIServiceLoader(scoped_ptr<ServiceLoader> real_loader,
+                                 shell::Context* context)
+    : loader_(real_loader.Pass()), context_(context) {
+}
+
+UIServiceLoader::~UIServiceLoader() {
+  context_->ui_loop()->PostTask(
+      FROM_HERE,
+      base::Bind(&UIServiceLoader::ShutdownOnUIThread, base::Unretained(this)));
+}
+
+void UIServiceLoader::LoadService(ServiceManager* manager,
+                                  const GURL& url,
+                                  ScopedMessagePipeHandle shell_handle) {
+  context_->ui_loop()->PostTask(
+      FROM_HERE,
+      base::Bind(
+          &UIServiceLoader::LoadServiceOnUIThread,
+          base::Unretained(this),
+          manager,
+          url,
+          base::Owned(new ScopedMessagePipeHandle(shell_handle.Pass()))));
+}
+
+void UIServiceLoader::OnServiceError(ServiceManager* manager, const GURL& url) {
+  context_->ui_loop()->PostTask(
+      FROM_HERE,
+      base::Bind(&UIServiceLoader::OnServiceErrorOnUIThread,
+                 base::Unretained(this),
+                 manager,
+                 url));
+}
+
+void UIServiceLoader::LoadServiceOnUIThread(
+    ServiceManager* manager,
+    const GURL& url,
+    ScopedMessagePipeHandle* shell_handle) {
+  if (!ui_loader_)
+    ui_loader_ = new UILoader(loader_.get());
+  ui_loader_->LoadService(manager, url, shell_handle->Pass());
+}
+
+void UIServiceLoader::OnServiceErrorOnUIThread(ServiceManager* manager,
+                                               const GURL& url) {
+  if (!ui_loader_)
+    ui_loader_ = new UILoader(loader_.get());
+  ui_loader_->OnServiceError(manager, url);
+}
+
+void UIServiceLoader::ShutdownOnUIThread() {
+  delete ui_loader_;
+  // Destroy |loader_| on the thread it's actually used on.
+  loader_.reset();
+}
+
+}  // namespace mojo