Issue 521- Inject our stylesheet on per-site basis rather than globally

lib/contentPolicy.js

Index: lib/contentPolicy.js
===================================================================
--- a/lib/contentPolicy.js
+++ b/lib/contentPolicy.js
@@ -139,90 +139,109 @@ let Policy = exports.Policy =
       Utils.styleService.unregisterSheet(collapseStyle, Ci.nsIStyleSheetService.USER_SHEET);
     })
     TimeLine.log("done registering stylesheet");
 
     TimeLine.leave("Done initializing content policy");
   },
 
   /**
+   * Checks whether a window or its parent is whitelisted or has a valid site-key.
+   * @param wnd {nsIDOMWindow}
+   */
+  shouldNeverBlockWindow: function(wnd)
+  {
+    let uri = wnd.document.documentURIObject;
+    if (!uri)
+      return true;
+
+    if (!Policy.isBlockableScheme(uri.scheme))
+      return true;
+
+    let topWnd = wnd.top;
+    if (!topWnd || !topWnd.location || !topWnd.location.href)
+      return true;
+
+    let testWnd = wnd;
+    let parentWndLocation = getWindowLocation(testWnd);
+    while (true)
+    {
+      let testWndLocation = parentWndLocation;
+      parentWndLocation = (testWnd == testWnd.parent ? testWndLocation : getWindowLocation(testWnd.parent));
+
+      let match = Policy.isWhitelisted(testWndLocation, parentWndLocation);
+
+      if (match == null)
+      {
+        let keydata = (testWnd.document && testWnd.document.documentElement ? testWnd.document.documentElement.getAttribute("data-adblockkey") : null);
+        if (keydata && keydata.indexOf("_") >= 0)
+        {
+          let [key, signature] = keydata.split("_", 2);
+          let keyMatch = defaultMatcher.matchesByKey(testWndLocation, key.replace(/=/g, ""), docDomain);
+          if (keyMatch && Utils.crypto)
+          {
+            // Website specifies a key that we know but is the signature valid?
+            let uri = Services.io.newURI(testWndLocation, null, null);
+            let params = [
+              uri.path.replace(/#.*/, ""),  // REQUEST_URI
+              uri.asciiHost,                // HTTP_HOST
+              Utils.httpProtocol.userAgent  // HTTP_USER_AGENT
+            ];
+            if (Utils.verifySignature(key, signature, params.join("\0")))
+              match = keyMatch;
+          }
+        }
+      }
+
+      if (match instanceof WhitelistFilter)
+      {
+        FilterStorage.increaseHitCount(match, wnd);
+        RequestNotifier.addNodeData(testWnd.document, topWnd, Policy.type.DOCUMENT, getHostname(parentWndLocation), false, testWndLocation, match);
+        return true;
+      }
+
+      if (testWnd.parent == testWnd)
+        break;
+      else
+        testWnd = testWnd.parent;
+    }
+
+    return false;
+  },
+
+  /**
    * Checks whether a node should be blocked, hides it if necessary
    * @param wnd {nsIDOMWindow}
    * @param node {nsIDOMElement}
    * @param contentType {String}
    * @param location {nsIURI}
    * @param collapse {Boolean} true to force hiding of the node
    * @return {Boolean} false if the node should be blocked
    */
   processNode: function(wnd, node, contentType, location, collapse)
   {
-    let topWnd = wnd.top;
-    if (!topWnd || !topWnd.location || !topWnd.location.href)
+    if (Policy.shouldNeverBlockWindow(wnd))
       return true;
 
+    let topWnd = wnd.top;
     let originWindow = Utils.getOriginWindow(wnd);
     let wndLocation = originWindow.location.href;
     let docDomain = getHostname(wndLocation);
-    let match = null;
-    if (!match && Prefs.enabled)
-    {
-      let testWnd = wnd;
-      let parentWndLocation = getWindowLocation(testWnd);
-      while (true)
-      {
-        let testWndLocation = parentWndLocation;
-        parentWndLocation = (testWnd == testWnd.parent ? testWndLocation : getWindowLocation(testWnd.parent));
-        match = Policy.isWhitelisted(testWndLocation, parentWndLocation);
-
-        if (!(match instanceof WhitelistFilter))
-        {
-          let keydata = (testWnd.document && testWnd.document.documentElement ? testWnd.document.documentElement.getAttribute("data-adblockkey") : null);
-          if (keydata && keydata.indexOf("_") >= 0)
-          {
-            let [key, signature] = keydata.split("_", 2);
-            let keyMatch = defaultMatcher.matchesByKey(testWndLocation, key.replace(/=/g, ""), docDomain);
-            if (keyMatch && Utils.crypto)
-            {
-              // Website specifies a key that we know but is the signature valid?
-              let uri = Services.io.newURI(testWndLocation, null, null);
-              let params = [
-                uri.path.replace(/#.*/, ""),  // REQUEST_URI
-                uri.asciiHost,                // HTTP_HOST
-                Utils.httpProtocol.userAgent  // HTTP_USER_AGENT
-              ];
-              if (Utils.verifySignature(key, signature, params.join("\0")))
-                match = keyMatch;
-            }
-          }
-        }
-
-        if (match instanceof WhitelistFilter)
-        {
-          FilterStorage.increaseHitCount(match, wnd);
-          RequestNotifier.addNodeData(testWnd.document, topWnd, Policy.type.DOCUMENT, getHostname(parentWndLocation), false, testWndLocation, match);
-          return true;
-        }
-
-        if (testWnd.parent == testWnd)
-          break;
-        else
-          testWnd = testWnd.parent;
-      }
-    }
 
     // Data loaded by plugins should be attached to the document
     if (contentType == Policy.type.OBJECT_SUBREQUEST && node instanceof Ci.nsIDOMElement)
       node = node.ownerDocument;
 
     // Fix type for objects misrepresented as frames or images
     if (contentType != Policy.type.OBJECT && (node instanceof Ci.nsIDOMHTMLObjectElement || node instanceof Ci.nsIDOMHTMLEmbedElement))
       contentType = Policy.type.OBJECT;
 
     let locationText = location.spec;
-    if (!match && contentType == Policy.type.ELEMHIDE)
+    let match = null;
+    if (contentType == Policy.type.ELEMHIDE)
     {
       let testWnd = wnd;
       let parentWndLocation = getWindowLocation(testWnd);
       while (true)
       {
         let testWndLocation = parentWndLocation;
         parentWndLocation = (testWnd == testWnd.parent ? testWndLocation : getWindowLocation(testWnd.parent));
         let parentDocDomain = getHostname(parentWndLocation);