Refactor OriginTrialPolicy to be an abstract interface in content/public/common

content/shell/common/shell_origin_trial_policy.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 "content/shell/common/shell_origin_trial_policy.h"
+
+namespace content {
+
+namespace {
+
+// This is the public key which the content shell will use to enable origin
+// trial features. Trial tokens for use in layout tests can be created with the
+// tool in /tools/origin_trials/generate_token.py, using the private key
+// contained in /tools/origin_trials/eftest.key.
+static const uint8_t kOriginTrialPublicKey[] = {
+    0x75, 0x10, 0xac, 0xf9, 0x3a, 0x1c, 0xb8, 0xa9, 0x28, 0x70, 0xd2,
+    0x9a, 0xd0, 0x0b, 0x59, 0xe1, 0xac, 0x2b, 0xb7, 0xd5, 0xca, 0x1f,
+    0x64, 0x90, 0x08, 0x8e, 0xa8, 0xe0, 0x56, 0x3a, 0x04, 0xd0,
+};
+}  // namespace
+
+ShellOriginTrialPolicy::ShellOriginTrialPolicy()
+    : public_key_(base::StringPiece(
+          reinterpret_cast<const char*>(kOriginTrialPublicKey),
+          arraysize(kOriginTrialPublicKey))) {}
+
+ShellOriginTrialPolicy::~ShellOriginTrialPolicy() {}
+
+base::StringPiece ShellOriginTrialPolicy::GetPublicKey() const {
+  return public_key_;
+}
+
+}  // namespace content