Move most Feature Policy code into content/

third_party/WebKit/Source/platform/feature_policy/FeaturePolicy.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 FeaturePolicy_h
 #define FeaturePolicy_h
 
 #include "platform/PlatformExport.h"
 #include "platform/weborigin/SecurityOrigin.h"
 #include "public/platform/WebFeaturePolicy.h"
 #include "wtf/RefPtr.h"
 #include "wtf/Vector.h"
 #include "wtf/text/WTFString.h"
 
 #include <memory>
 
 namespace blink {
 
-// Feature Policy is a mechanism for controlling the availability of web
-// platform features in a frame, including all embedded frames. It can be used
-// to remove features, automatically refuse API permission requests, or modify
-// the behaviour of features. (The specific changes which are made depend on the
-// feature; see the specification for details).
-//
-// Policies can be defined in the HTTP header stream, with the |Feature-Policy|
-// HTTP header, or can be set by |enable| and |disable| attributes on the iframe
-// element which embeds the document.
-//
-// See https://wicg.github.io/FeaturePolicy/
-//
-// Key concepts:
-//
-// Features
-// --------
-// Features which can be controlled by policy are defined as instances of the
-// FeaturePoliicy::Feature struct. The features are referenced by pointer, so
-// only a single instance of each feature should be defined. The features which
-// are declared in the feature policy specification are all defined in
-// |FeaturePolicy.cpp|.
-//
-// Whitelists
-// ----------
-// Policies are defined as a mapping of feaure names to whitelists. Whitelists
-// are collections of origins, although two special terms can be used when
-// declaring them:
-//   "self" refers to the orgin of the frame which is declaring the policy.
-//   "*" refers to all origins; any origin will match a whitelist which contains
-//     it.
-//
-// Defaults
-// --------
-// Each defined feature has a default policy, which determines whether the
-// feature is available when no policy has been declared, ans determines how the
-// feature is inherited across origin boundaries.
-//
-// If the default policy  is in effect for a frame, then it controls how the
-// feature is inherited by any cross-origin iframes embedded by the frame. (See
-// the comments below in FeaturePolicy::DefaultPolicy for specifics)
-//
-// Policy Inheritance
-// ------------------
-// Policies in effect for a frame are inherited by any child frames it embeds.
-// Unless another policy is declared in the child, all same-origin children will
-// receive the same set of enables features as the parent frame. Whether or not
-// features are inherited by cross-origin iframes without an explicit policy is
-// determined by the feature's default policy. (Again, see the comments in
-// FeaturePolicy::DefaultPolicy for details)
-
-class PLATFORM_EXPORT FeaturePolicy final {
- public:
-  // Represents a collection of origins which make up a whitelist in a feature
-  // policy. This collection may be set to match every origin (corresponding to
-  // the "*" syntax in the policy string, in which case the contains() method
-  // will always return true.
-  class Whitelist final {
-   public:
-    static std::unique_ptr<Whitelist> from(
-        const WebFeaturePolicy::ParsedWhitelist&);
-
-    Whitelist();
-
-    // Adds a single origin to the whitelist.
-    void add(RefPtr<SecurityOrigin>);
-
-    // Adds all origins to the whitelist.
-    void addAll();
-
-    // Returns true if the given origin has been added to the whitelist.
-    bool contains(const SecurityOrigin&) const;
-    String toString();
-
-   private:
-    bool m_matchesAllOrigins;
-    Vector<RefPtr<SecurityOrigin>> m_origins;
-  };
-
-  // The FeaturePolicy::FeatureDefault enum defines the default enable state for
-  // a feature when neither it nor any parent frame have declared an explicit
-  // policy. The three possibilities map directly to Feature Policy Whitelist
-  // semantics.
-  enum class FeatureDefault {
-    // Equivalent to []. If this default policy is in effect for a frame, then
-    // the feature will not be enabled for that frame or any of its children.
-    DisableForAll,
-
-    // Equivalent to ["self"]. If this default policy is in effect for a frame,
-    // then the feature will be enabled for that frame, and any same-origin
-    // child frames, but not for any cross-origin child frames.
-    EnableForSelf,
-
-    // Equivalent to ["*"]. If in effect for a frame, then the feature is
-    // enabled for that frame and all of its children.
-    EnableForAll
-  };
-
-  // The FeaturePolicy::Feature struct is used to define all features under
-  // control of Feature Policy. There should only be one instance of this struct
-  // for any given feature (declared below).
-  struct Feature {
-    // The name of the feature, as it should appear in a policy string
-    const char* const featureName;
-
-    // Controls whether the feature should be available in the platform by
-    // default, in the absence of any declared policy.
-    FeatureDefault defaultPolicy;
-  };
-
-  using FeatureList = const Vector<const FeaturePolicy::Feature*>;
-
-  // Converts a JSON feature policy string into a vector of whitelists, one for
-  // each feature specified. Unrecognized features are parsed and included
-  // but will be filtered out when the policy is constructed. If |messages| is
-  // not null, then any errors in the input will cause an error message to be
-  // appended to it.
-  static WebParsedFeaturePolicy parseFeaturePolicy(const String& policy,
-                                                   RefPtr<SecurityOrigin>,
-                                                   Vector<String>* messages);
-
-  static std::unique_ptr<FeaturePolicy> createFromParentPolicy(
-      const FeaturePolicy* parent,
-      RefPtr<SecurityOrigin>);
-
-  // Sets the declared policy from the parsed Feature-Policy HTTP header.
-  // Unrecognized features will be ignored.
-  void setHeaderPolicy(const WebParsedFeaturePolicy&);
-
-  // Returns whether or not the given feature is enabled by this policy.
-  bool isFeatureEnabledForOrigin(const Feature&, const SecurityOrigin&) const;
-
-  // Returns whether or not the given feature is enabled for the frame that owns
-  // the policy.
-  bool isFeatureEnabled(const Feature&) const;
-
-  // Returns the list of features which can be controlled by Feature Policy.
-  static FeatureList& getDefaultFeatureList();
-
-  String toString();
-
- private:
-  friend class FeaturePolicyTest;
-  friend class FeaturePolicyInFrameTest;
-
-  FeaturePolicy(RefPtr<SecurityOrigin>, FeatureList& features);
-
-  static std::unique_ptr<FeaturePolicy> createFromParentPolicy(
-      const FeaturePolicy* parent,
-      RefPtr<SecurityOrigin>,
-      FeatureList& features);
-
-  RefPtr<SecurityOrigin> m_origin;
-
-  // Records whether or not each feature was enabled for this frame by its
-  // parent frame.
-  // TODO(iclelland): Generate, instead of this map, a set of bool flags, one
-  // for each feature, as all features are supposed to be represented here.
-  HashMap<const Feature*, bool> m_inheritedFeatures;
-
-  // Map of feature names to declared whitelists. Any feature which is missing
-  // from this map should use the inherited policy.
-  HashMap<const Feature*, std::unique_ptr<Whitelist>> m_headerWhitelists;
-
-  // Contains the set of all features which can be controlled by this policy.
-  FeatureList& m_features;
-
-  DISALLOW_COPY_AND_ASSIGN(FeaturePolicy);
-};
-
-// Declarations for all features currently under control of the Feature Policy
-// mechanism should be placed here.
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kDocumentCookie;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kDocumentDomain;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kDocumentWrite;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kGeolocationFeature;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kFullscreenFeature;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kMidiFeature;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kNotificationsFeature;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kPaymentFeature;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kPushFeature;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kSyncScript;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kSyncXHR;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kUsermedia;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kVibrateFeature;
-extern const PLATFORM_EXPORT FeaturePolicy::Feature kWebRTC;
+// Converts a JSON feature policy string into a vector of whitelists, one for
+// each feature specified. Unrecognized features are parsed and included
+// but will be filtered out when the policy is constructed. If |messages| is
+// not null, then any errors in the input will cause an error message to be
+// appended to it.
+PLATFORM_EXPORT WebParsedFeaturePolicyHeader
+parseFeaturePolicy(const String& policy,
+                   RefPtr<SecurityOrigin>,
+                   Vector<String>* messages);
 
 }  // namespace blink
 
 #endif  // FeaturePolicy_h