Remove all blimp browsertests.

blimp/engine/browser_tests/blimp_contents_view_readback_helper.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 "blimp/engine/browser_tests/blimp_contents_view_readback_helper.h"
-
-#include "base/bind.h"
-#include "third_party/skia/include/core/SkBitmap.h"
-
-namespace blimp {
-
-BlimpContentsViewReadbackHelper::BlimpContentsViewReadbackHelper()
-    : event_(base::WaitableEvent::ResetPolicy::MANUAL,
-             base::WaitableEvent::InitialState::NOT_SIGNALED),
-      weak_ptr_factory_(this) {}
-
-BlimpContentsViewReadbackHelper::~BlimpContentsViewReadbackHelper() = default;
-
-client::BlimpContentsView::ReadbackRequestCallback
-BlimpContentsViewReadbackHelper::GetCallback() {
-  return base::Bind(&BlimpContentsViewReadbackHelper::OnReadbackComplete,
-                    weak_ptr_factory_.GetWeakPtr());
-}
-
-SkBitmap* BlimpContentsViewReadbackHelper::GetBitmap() const {
-  return bitmap_.get();
-}
-
-void BlimpContentsViewReadbackHelper::OnReadbackComplete(
-    std::unique_ptr<SkBitmap> bitmap) {
-  bitmap_ = std::move(bitmap);
-  event_.Signal();
-}
-
-}  // namespace blimp