[Extensions] Start making chrome://extensions use extensions APIs

Allow chrome://extensions to use the developerPrivate and
management apis, and make it do so for enabling/disabling
extensions.
Also, shave yaks:
- Make management api check requirements for extensions.
- Make feature provider aware of complex parents.
And bonus:
- Remove WeakPtr interface from RequirementsChecker

BUG=461039

Review URL: https://codereview.chromium.org/951633002

Cr-Commit-Position: refs/heads/master@{#317871}

1 files changed, 38 insertions, 0 deletions

diff --git a/extensions/browser/requirements_checker.h b/extensions/browser/requirements_checker.h
new file mode 100644
index 0000000..a5c1614
--- /dev/null
+++ b/extensions/browser/requirements_checker.h
@@ -0,0 +1,38 @@
+// Copyright 2015 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 CHROME_BROWSER_EXTENSIONS_REQUIREMENTS_CHECKER_H_
+#define CHROME_BROWSER_EXTENSIONS_REQUIREMENTS_CHECKER_H_
+
+#include <vector>
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+
+namespace extensions {
+class Extension;
+
+// Validates the 'requirements' extension manifest field. This is an
+// asynchronous process that involves several threads, but the public interface
+// of this class (including constructor and destructor) must only be used on
+// the UI thread.
+class RequirementsChecker {
+ public:
+  virtual ~RequirementsChecker() {}
+
+  using RequirementsCheckedCallback =
+      base::Callback<void(const std::vector<std::string>& /* requirements */)>;
+
+  // The vector passed to the callback are any localized errors describing
+  // requirement violations. If this vector is non-empty, requirements checking
+  // failed. This should only be called once. |callback| will always be invoked
+  // asynchronously on the UI thread. |callback| will only be called once, and
+  // will be reset after called.
+  virtual void Check(const scoped_refptr<const Extension>& extension,
+                     const RequirementsCheckedCallback& callback) = 0;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_REQUIREMENTS_CHECKER_H_