Remove all blimp client code.

blimp/client/core/feedback/blimp_feedback_data.h

-// 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.
-
-#ifndef BLIMP_CLIENT_CORE_FEEDBACK_BLIMP_FEEDBACK_DATA_H_
-#define BLIMP_CLIENT_CORE_FEEDBACK_BLIMP_FEEDBACK_DATA_H_
-
-#include <string>
-#include <unordered_map>
-
-namespace blimp {
-namespace client {
-class BlimpContentsManager;
-
-// Denotes whether Blimp is supported in the current.
-extern const char kFeedbackSupportedKey[];
-// Denotes whether there exists any visible BlimpContents.
-extern const char kFeedbackHasVisibleBlimpContents[];
-// Denotes the user name for the current logged in user.
-extern const char kFeedbackUserNameKey[];
-
-// Creates a data object containing data about Blimp to be used for feedback.
-std::unordered_map<std::string, std::string> CreateBlimpFeedbackData(
-    BlimpContentsManager* blimp_contents_manager,
-    const std::string& username);
-
-}  // namespace client
-}  // namespace blimp
-
-#endif  // BLIMP_CLIENT_CORE_FEEDBACK_BLIMP_FEEDBACK_DATA_H_