Support "always allow" for runtime script execution

chrome/browser/extensions/active_script_controller.cc

Index: chrome/browser/extensions/active_script_controller.cc
diff --git a/chrome/browser/extensions/active_script_controller.cc b/chrome/browser/extensions/active_script_controller.cc
index 1b35b2872c9415706f9bd7585315856576cdc57b..1a372e7d4b441599fec6520f910b116b82e6f36f 100644
--- a/chrome/browser/extensions/active_script_controller.cc
+++ b/chrome/browser/extensions/active_script_controller.cc
@@ -13,19 +13,24 @@
 #include "chrome/browser/extensions/extension_action.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/extensions/location_bar_controller.h"
+#include "chrome/browser/extensions/permissions_updater.h"
 #include "chrome/browser/extensions/tab_helper.h"
+#include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sessions/session_id.h"
 #include "chrome/common/extensions/api/extension_action/action_info.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
+#include "extensions/browser/extension_prefs.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/extension_set.h"
 #include "extensions/common/feature_switch.h"
 #include "extensions/common/manifest.h"
+#include "extensions/common/manifest_handlers/permissions_parser.h"
+#include "extensions/common/permissions/permission_set.h"
 #include "extensions/common/permissions/permissions_data.h"
 #include "ipc/ipc_message_macros.h"
 
@@ -100,6 +105,49 @@ void ActiveScriptController::OnAdInjectionDetected(
       ad_injectors.size() - num_preventable_ad_injectors);
 }
 
+void ActiveScriptController::AddPersistedPermission(
+    const Extension* extension) {
+  GURL url = web_contents()->GetVisibleURL();
+  URLPattern pattern(extensions::UserScript::ValidUserScriptSchemes());
+  pattern.SetScheme(url.scheme());
+  pattern.SetHost(url.host());

[not at google - send to devlin, 2014/08/07 22:03:45]

should probably also set port here.

[gpdavis, 2014/08/08 00:51:43]

Done.

+  pattern.SetPath("/*");
+
+  extensions::URLPatternSet new_explicit_hosts;
+  extensions::URLPatternSet new_scriptable_hosts;
+
+  scoped_refptr<const PermissionSet> withheld_permissions =
+      extension->permissions_data()->withheld_permissions();
+  if (withheld_permissions->explicit_hosts().MatchesURL(url))
+    new_explicit_hosts.AddPattern(pattern);
+  if (withheld_permissions->scriptable_hosts().MatchesURL(url))
+    new_scriptable_hosts.AddPattern(pattern);
+
+  scoped_refptr<extensions::PermissionSet> new_permissions =
+      new extensions::PermissionSet(extensions::APIPermissionSet(),
+                                    extensions::ManifestPermissionSet(),
+                                    new_explicit_hosts,
+                                    new_scriptable_hosts);
+
+  // Update permissions for the session. This adds |new_permissions| to active
+  // permissions and granted permissions.
+  extensions::PermissionsUpdater updater(
+      Profile::FromBrowserContext(web_contents()->GetBrowserContext()));

[not at google - send to devlin, 2014/08/07 22:03:45]

you don't need to cast this to a Profile*, it takes a BrowserContext. so just
web_contents()->GetBrowserContext()

[gpdavis, 2014/08/08 00:51:43]

Done.

+  updater.AddPermissions(extension, new_permissions.get());

[gpdavis, 2014/08/07 20:50:39]

So here we AddPermissions, which will immediately make it active for the current
session, and add to granted which will allow us to persist the permissions
between sessions.

+
+  UMA_HISTOGRAM_COUNTS_100(

[not at google - send to devlin, 2014/08/07 22:03:45]

hmmmmm so I don't think this actually is right, sorry. An extension can request:

{
  "https://*.google.com/*",
  "http://*/*"
}

the http://*/* will be withheld, but the https won't, so the
GetEffectiveHostPermissions() count will be off by 1.

a better estimate would be EffectiveHostPermissions.size -
union(ScriptableHostPermissions, RequiredHostPermissions).size

[gpdavis, 2014/08/08 00:51:43]

Which permissions are you talking about here?  Withheld scriptable hosts and
extension required permissions (as in,
PermissionsParser::GetRequiredPermissions()?).

[not at google - send to devlin, 2014/08/08 14:31:28]

ah. oh man, optional permissions do complicate things here.

alright, I think that's fine and we can ignore optional permissions.
- it's a corner case.
- I think that we normalise optional permissions such that they can't be a
subset of required permissions.
- even if not, if we include the number of optional permissions granted as well,
that's not necessarily wrong.

so the answer to your question is yes, Required.

[gpdavis, 2014/08/08 18:07:35]

So then, the size of withheld_permissions->scriptable_hosts() U
PermissionsParser::GetRequiredPermissions()->scriptable_hosts()?

+      "Extensions.ActiveScriptController.PersistedPermissionCount",

[not at google - send to devlin, 2014/08/07 22:03:45]

AlwaysRunCount would be better.

[gpdavis, 2014/08/08 00:51:43]

Done.

+      extension->permissions_data()->GetEffectiveHostPermissions().size());
+
+  // Allow current tab to run injection.
+  OnClicked(extension);
+}
+
+bool ActiveScriptController::HasActiveScriptAction(
+    const Extension* extension) {
+  return enabled_ && active_script_actions_.count(extension->id()) > 0;
+}
+
 ExtensionAction* ActiveScriptController::GetActionForExtension(
     const Extension* extension) {
   if (!enabled_ || pending_requests_.count(extension->id()) == 0)