PS - Showing permission prompt for activeTab

chrome/browser/extensions/active_tab_permission_granter.cc

Index: chrome/browser/extensions/active_tab_permission_granter.cc
diff --git a/chrome/browser/extensions/active_tab_permission_granter.cc b/chrome/browser/extensions/active_tab_permission_granter.cc
index 1732c6070d7d14ba03f78769f85c6b040245a123..43ec5a812bb9fde8bfd1aeddde4ac916e298f550 100644
--- a/chrome/browser/extensions/active_tab_permission_granter.cc
+++ b/chrome/browser/extensions/active_tab_permission_granter.cc
@@ -66,6 +66,8 @@ void SendMessageToProcesses(
     tab_process->Send(create_message.Run(false));
 }
 
+ActiveTabPermissionGranter::Delegate* g_delegate = nullptr;
+
 }  // namespace
 
 ActiveTabPermissionGranter::ActiveTabPermissionGranter(
@@ -80,6 +82,14 @@ ActiveTabPermissionGranter::ActiveTabPermissionGranter(
 
 ActiveTabPermissionGranter::~ActiveTabPermissionGranter() {}
 
+// static
+void ActiveTabPermissionGranter::SetPlatformDelegate(Delegate* delegate) {
+  // Disallow setting it twice (but allow resetting - don't forget to free in
+  // that case).
+  CHECK(!g_delegate || !delegate);
+  g_delegate = delegate;
+}
+
 void ActiveTabPermissionGranter::GrantIfRequested(const Extension* extension) {
   if (granted_extensions_.Contains(extension->id()))
     return;
@@ -89,11 +99,14 @@ void ActiveTabPermissionGranter::GrantIfRequested(const Extension* extension) {
 
   const PermissionsData* permissions_data = extension->permissions_data();
 
+  bool active_tab_granted = !g_delegate ||
+      g_delegate->ActiveTabPermissionGranted(extension, web_contents());
   // If the extension requested all-hosts but has had it withheld, we grant it
   // active tab-style permissions, even if it doesn't have the activeTab
   // permission in the manifest.
-  if (permissions_data->HasAPIPermission(APIPermission::kActiveTab) ||
-      permissions_data->HasWithheldImpliedAllHosts()) {
+  if (permissions_data->HasWithheldImpliedAllHosts() ||

[Andrew T Wilson (Slow), 2017/05/09 13:29:29]

Why isn't HasWithheldImpliedAllHosts() subject to active_tab_granted as well?

[Ivan Šandrk, 2017/05/10 10:01:28]

It's unrelated to activeTab functionality. Afaict it's used to temporarily
withhold all_urls host permissions.

I mean they are related, but in the sense that either of them can grant the
extension access to the current tab/page (activeTab needs to be invoked, while
all_urls just gives blanket access to all pages). We block all_urls in public
sessions.

+      (active_tab_granted &&
+           permissions_data->HasAPIPermission(APIPermission::kActiveTab))) {
     new_hosts.AddOrigin(UserScript::ValidUserScriptSchemes(),
                         web_contents()->GetVisibleURL().GetOrigin());
     new_apis.insert(APIPermission::kTab);