CSP 1.1: Workers may have their own policies.

According to [1], we have consensus that web workers ought not always
inherit their owner documents' set of policies, but instead be governed
by whatever policy is delivered along with the worker's script.

Workers should inherit their owner document's set of policies only when
they are created from URLs with unique origins (such as the various
types of non-hierarchical URLs we care about: blob, filesystem, data,
etc.).

This patch attempts to clarify that, and also clarifies that
'importScripts' ought to be filtered through the currently active set of
policies.

[1]: http://lists.w3.org/Archives/Public/public-webappsec/2013Dec/0007.html

csp-specification.dev.html

@@ -119,7 +119,7 @@ <h3>Key Concepts and Terminology</h3>
 
         <p>The term <dfn id="origin">origin</dfn> is defined in the Origin specification. [[!RFC6454]]</p>
 
-        <p>The term <dfn>globally unique identifier</dfn> is defined in section 4 of the Origin specification. [[!RFC6454]]</p>
+        <p>The term <dfn>globally unique identifier</dfn> is defined in section 4 of the Origin specification. Note that URLs that do not use hierarchical elements as naming authorities have origins which are globally unique identifiers. [[!RFC6454]]</p>
 
         <p>The term <dfn>URI</dfn> is defined in the URI specification.  [[!URI]]</p>
 
@@ -925,13 +925,29 @@ <h3>Processing Model</h3>
         [[!WEBWORKERS]]</p>
 
         <ul>
-          <li>If the user agent is enforcing a policy for the <var>owner
-          document</var>, the user agent MUST enforce the policy for the
-          worker.</li>
-
-          <li>If the user agent is monitoring a policy for the <var>owner
-          document</var>, the user agent MUST monitor the policy for the
-          worker.</li>
+          <li>If the worker's script's origin is a <a href="#dfn-globally-unique-identifier">globally unique identifier</a>
+          (for example, the worker's script's URL has a scheme of
+          <code>data</code>, <code>blob</code>, or <code>file</code>), then:
+          <ul>
+            <li>If the user agent is enforcing a CSP policy for the <var>owner
+            document</var>, the user agent MUST enforce the CSP policy for the
+            worker.</li>
+
+            <li>If the user agent is monitoring a CSP policy for the <var>owner
+            document</var>, the user agent MUST monitor the CSP policy for the
+            worker.</li>
+          </ul></li>
+          <li>Otherwise:
+          <ul>
+            <li>If the worker's script is delivered with a <code>Content-Security-Policy</code>
+            HTTP header containing the value <var>policy</var>, the user agent MUST
+            <a href="#enforce">enforce <var>policy</var></a> for the
+            worker.</li>
+            <li>If the worker's script is delivered with a <code>Content-Security-Policy-Report-Only</code>
+            HTTP header containing the value <var>policy</var>, the user agent MUST
+            <a href="#monitor">monitor <var>policy</var></a> for the
+            worker.</li>
+          </ul></li>
         </ul>
 
         <p>Whenever a user agent creates a <a
@@ -1898,7 +1914,10 @@ <h3><code>script-src</code></h3>
           <a href="#dfn-allowed-script-sources">allowed script sources</a>.</li>
 
           <li>Requesting a script while processing the
-          <code>Worker</code> or <code>SharedWorker</code> constructors.</li>
+          <code>Worker</code> or <code>SharedWorker</code> constructors. [[!WEBWORKERS]]</li>
+
+          <li>Requesting a script while invoking the <code>importScripts</code>
+          method on a WorkerGlobalScope object. [[!WEBWORKERS]]</li>
 
           <li>Requesting an HTML component, such as
           when processing the <code>href</code> attribute of a <code>link</code>