Walk ancestor tree to decide if powerful features should be allowed

As specified in
https://w3c.github.io/webappsec/specs/powerfulfeatures/#settings-privileged,
deciding if a powerful feature should be allowed involves walking up the
ancestor chain and deciding if each origin is "potentially trustworthy."
This CL adds a |isPrivilegedContext| method to |ExecutionContext|, which
calls |isPotentiallyTrustworthy| for each origin in the ancestor chain.

Because some sites heavily rely on the ability to use WebCrypto when the
ancestor chain includes an insecure origin, there is a flag to skip the
ancestor check, used only from WebCrypto.

This CL also factors out the layout test helper |get_host_info()| into
its own file, since it is used by many tests other than ServiceWorker
tests.

This CL does not yet implement ancestor-chain-checking for Workers
(i.e. checking if the responsible document's origin and all of its
ancestors are potentially trustworthy when a worker wants to access a
powerful feature). That will be a follow-up CL.

BUG=474710

Review URL: https://codereview.chromium.org/1077083004

git-svn-id: svn://svn.chromium.org/blink/trunk@193883 bbb929c8-8fbe-4397-9dbb-9b2b20218538

1 files changed, 5 insertions, 6 deletions

diff --git a/third_party/WebKit/public/web/WebSecurityOrigin.h b/third_party/WebKit/public/web/WebSecurityOrigin.h
index 3ba25b4..3930f65 100644
--- a/third_party/WebKit/public/web/WebSecurityOrigin.h
+++ b/third_party/WebKit/public/web/WebSecurityOrigin.h
@@ -92,12 +92,11 @@ public:
     // from a given security origin to receive contents from a given URL.
     BLINK_PLATFORM_EXPORT bool canRequest(const WebURL&) const;
 
-    // A "secure origin" as defined by [1] are those that load resources either
-    // from the local machine (necessarily trusted) or over the network from a
-    // cryptographically-authenticated server.
-    //
-    // [1] http://www.chromium.org/Home/chromium-security/security-faq#TOC-Which-origins-are-secure-
-    BLINK_PLATFORM_EXPORT bool canAccessFeatureRequiringSecureOrigin(WebString& errorMessage) const;
+    // Returns true if the origin loads resources either from the local
+    // machine or over the network from a
+    // cryptographically-authenticated origin, as described in
+    // https://w3c.github.io/webappsec/specs/powerfulfeatures/#is-origin-trustworthy.
+    BLINK_PLATFORM_EXPORT bool isPotentiallyTrustworthy(WebString& errorMessage) const;
 
     // Returns a string representation of the WebSecurityOrigin.  The empty
     // WebSecurityOrigin is represented by "null".  The representation of a