Add ProcessControlImpl, the default ProcessControl implementation.

content/child/process_control_impl.cc

+// Copyright 2015 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/child/process_control_impl.h"
+
+#include "base/stl_util.h"
+#include "content/public/common/content_client.h"
+#include "mojo/shell/static_application_loader.h"

[Ken Rockot(use gerrit already), 2015/08/19 23:07:34]

This shouldn't be necessary (and so you can also remove mojo/shell from DEPS)

[xhwang, 2015/08/20 00:43:34]

I actually need it for the Load() call on l.40.

+#include "url/gurl.h"
+
+namespace content {
+
+ProcessControlImpl::ProcessControlImpl() {
+}
+
+ProcessControlImpl::~ProcessControlImpl() {
+  STLDeleteValues(&url_to_loader_map_);
+}
+
+void ProcessControlImpl::LoadApplication(
+    const mojo::String& url,
+    mojo::InterfaceRequest<mojo::Application> request,
+    const LoadApplicationCallback& callback) {
+  // Only register loaders when we need it.
+  if (!has_registered_loaders) {
+    DCHECK(url_to_loader_map_.empty());
+    RegisterApplicationLoaders(&url_to_loader_map_);
+    has_registered_loaders = true;
+  }
+
+  GURL application_url = GURL(url.To<std::string>());
+  auto it = url_to_loader_map_.find(application_url);
+  if (it == url_to_loader_map_.end()) {
+    callback.Run(false);
+    return;
+  }
+
+  callback.Run(true);
+  it->second->Load(application_url, request.Pass());
+}
+
+}  // namespace content