Support "always allow" for runtime script execution

chrome/browser/extensions/permissions_updater.cc

Index: chrome/browser/extensions/permissions_updater.cc
diff --git a/chrome/browser/extensions/permissions_updater.cc b/chrome/browser/extensions/permissions_updater.cc
index 5f2f62981d5889f7db19804d7734561aaaac5b9f..3e63c195a47449a1080d9f16bcbc335511d72c76 100644
--- a/chrome/browser/extensions/permissions_updater.cc
+++ b/chrome/browser/extensions/permissions_updater.cc
@@ -36,15 +36,24 @@ namespace permissions = api::permissions;
 
 namespace {
 
+URLPatternSet FilterSingleOriginPermissions(const URLPatternSet& permissions) {
+  URLPatternSet single_origin_permissions;
+  for (URLPatternSet::const_iterator iter = permissions.begin();
+       iter != permissions.end();
+       ++iter) {
+    if (iter->MatchesSingleOrigin())
+      single_origin_permissions.AddPattern(*iter);
+  }
+  return single_origin_permissions;
+}
+
 // Returns a PermissionSet that has the active permissions of the extension,
 // bounded to its current manifest.
 scoped_refptr<const PermissionSet> GetBoundedActivePermissions(
-    const Extension* extension, ExtensionPrefs* extension_prefs) {
+    const Extension* extension, const PermissionSet* active_permissions) {
   // If the extension has used the optional permissions API, it will have a
   // custom set of active permissions defined in the extension prefs. Here,
   // we update the extension's active permissions based on the prefs.
-  scoped_refptr<const PermissionSet> active_permissions =
-      extension_prefs->GetActivePermissions(extension->id());
   if (!active_permissions)
     return extension->permissions_data()->active_permissions();
 
@@ -144,9 +153,10 @@ void PermissionsUpdater::GrantActivePermissions(const Extension* extension) {
 }
 
 void PermissionsUpdater::InitializePermissions(const Extension* extension) {
+  scoped_refptr<const PermissionSet> active_permissions = ExtensionPrefs::Get(
+      browser_context_)->GetActivePermissions(extension->id());
   scoped_refptr<const PermissionSet> bounded_active =
-      GetBoundedActivePermissions(extension,
-                                  ExtensionPrefs::Get(browser_context_));
+      GetBoundedActivePermissions(extension, active_permissions);

[not at google - send to devlin, 2014/08/12 23:13:18]

active_permissions.get() ?

[gpdavis, 2014/08/13 00:08:24]

Ah, oops, missed that.  Looks like the compiler knows how to convert the smart
pointer, but there's no reason not to be concise.  Done.

[not at google - send to devlin, 2014/08/13 01:02:59]

Wow, what platform are you compiling on?

[gpdavis, 2014/08/13 01:14:50]

Ubuntu 12.04.  I didn't even get a compiler warning about it *shrug*

 
   // We withhold permissions iff the switch to do so is enabled, the extension
   // shows up in chrome:extensions (so the user can grant withheld permissions),
@@ -175,6 +185,22 @@ void PermissionsUpdater::InitializePermissions(const Extension* extension) {
                           &granted_scriptable_hosts,
                           &withheld_scriptable_hosts);
 
+  // After withholding permissions, add back any origins to the active set that
+  // may have been lost during the set operations that would have dropped them.
+  // For example, the union of <all_urls> and <anything> is <all_urls>, so we
+  // may lose the <anything>. However, that <anything> is important once
+  // <all_urls> is stripped during withholding.
+  if (active_permissions) {
+    URLPatternSet::CreateUnion(
+        FilterSingleOriginPermissions(active_permissions->explicit_hosts()),
+        granted_explicit_hosts,
+        &granted_explicit_hosts);

[not at google - send to devlin, 2014/08/12 23:13:18]

I'm not so sure about writing the union to one of the inputs :\ i.e. the fact
that |granted_explicit_hosts| is used both as an in-param and an out-param looks
problematic.

Luckily, you can write this much nicer anyway:

granted_explicit_hosts.AddPatterns(FilterSingleOriginPermissions(..));
granted_scriptable_hosts...

[gpdavis, 2014/08/13 00:08:24]

Fair enough.  That is much simpler anyway.

+    URLPatternSet::CreateUnion(
+        FilterSingleOriginPermissions(active_permissions->scriptable_hosts()),
+        granted_scriptable_hosts,
+        &granted_scriptable_hosts);
+  }
+
   bounded_active = new PermissionSet(bounded_active->apis(),
                                      bounded_active->manifest_permissions(),
                                      granted_explicit_hosts,