Add BlimpClientContext and factory with real and dummy implementation

chrome/browser/android/blimp/blimp_contents_profile_attachment.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 "chrome/browser/android/blimp/blimp_contents_profile_attachment.h"
+
+#include "base/logging.h"
+#include "base/supports_user_data.h"
+#include "blimp/client/public/blimp_contents.h"
+
+namespace {
+const char kBlimpContentsProfileAttachment[] =
+    "blimp_contents_profile_attachment";
+
+// A holder struct for a Profile that can be used as data.
+struct Attachment : public base::SupportsUserData::Data {
+  Profile* profile;
+};
+
+}  // namespace
+
+void AttachProfileToBlimpContents(blimp::client::BlimpContents* blimp_contents,
+                                  Profile* profile) {
+  DCHECK(profile);
+  Attachment* attachment = new Attachment;
+  attachment->profile = profile;
+  blimp_contents->SetUserData(kBlimpContentsProfileAttachment, attachment);
+}
+
+Profile* GetProfileFromBlimpContents(
+    blimp::client::BlimpContents* blimp_contents) {
+  Attachment* attachment = static_cast<Attachment*>(
+      blimp_contents->GetUserData(kBlimpContentsProfileAttachment));
+  DCHECK(attachment);
+  return attachment->profile;
+}