Clean content_settings_pattern_parser.* from unnecessary dependencies.

components/content_settings/core/common/embedder_variables.h

+// Copyright (c) 2014 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 COMPONENTS_CONTENT_SETTINGS_CORE_COMMON_EMBEDDER_VARIABLES_H_
+#define COMPONENTS_CONTENT_SETTINGS_CORE_COMMON_EMBEDDER_VARIABLES_H_
+
+#include <string>
+
+#include "base/macros.h"
+
+namespace content_settings {
+
+// Sets the scheme that doesn't support domain wildcard and port.
+// Needs to be called by the embedder before using ContentSettingsPattern.
+// |scheme| can't be NULL, and the pointed string must remain alive until the

[blundell, 2014/08/26 09:16:57]

Is there a reason not to have a global variable internally, pass the string by
const ref, and copy it? That seems like it would be a friendlier API.

[vasilii, 2014/08/26 12:18:19]

The reason for that is we dislike global objects with the destructor
https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/FM8C-qPm5fk
We also have a warning for this 'enable_wexit_time_destructors'. For some reason
it's off in componenets/. I included it for the content_settings component.

[Bernhard Bauer, 2014/08/26 12:32:08]

FWIW, you could still leak the string at shutdown (either via
base::LazyInstance<>::Leaky or a plain std::string*).

+// Chrome terminates.
+void SetNonWildcardDomainNonPortScheme(const char* scheme);
+
+// Compares |scheme| against the scheme set by the embedder.
+bool IsNonWildcardDomainNonPortScheme(const std::string& scheme);

[blundell, 2014/08/26 09:16:57]

is this function used outside of ContentSettingsPattern? If not, I'd be inclined
to just put SetNonWildcardDomainNonPortScheme into ContentSettingsPattern and
have ContentSettingsPattern use the global directly internally.

[vasilii, 2014/08/26 12:18:18]

In content_settings_pattern_parser.cc. I see that kExtensionScheme is used at
least in cookie_settings.cc, host_content_settings_map.cc. They are to be
componentised. 

[blundell, 2014/08/26 12:21:38]

Hmm, is the usage in the latter two files the same semantically, i.e., will it
make sense to replace it by a call to IsNonWildcardDomainNonPortScheme()?

I have no problem with the existence of this file but I don't like the name
embedder_variables.*. I was having trouble trying to think of a better name so
thought maybe we could just get rid of the file altogether :).

[vasilii, 2014/08/27 11:39:32]

Removed the files.

+
+}  // namespace content_settings
+#endif  // COMPONENTS_CONTENT_SETTINGS_CORE_COMMON_EMBEDDER_VARIABLES_H_