Allow extensions to specify that they are not allowed in incognito mode.

extensions/common/extension.cc

Index: extensions/common/extension.cc
diff --git a/extensions/common/extension.cc b/extensions/common/extension.cc
index 8aefc6af954bef0c8ff3b23e2b83debd4f06667a..f436d7c68dc01dbf4467d561680291f398d312be 100644
--- a/extensions/common/extension.cc
+++ b/extensions/common/extension.cc
@@ -28,6 +28,7 @@
 #include "extensions/common/manifest.h"
 #include "extensions/common/manifest_constants.h"
 #include "extensions/common/manifest_handler.h"
+#include "extensions/common/manifest_handlers/incognito_info.h"
 #include "extensions/common/manifest_handlers/permissions_parser.h"
 #include "extensions/common/permissions/permission_set.h"
 #include "extensions/common/permissions/permissions_data.h"
@@ -440,7 +441,8 @@ bool Extension::is_theme() const {
 
 bool Extension::can_be_incognito_enabled() const {
   // Only component platform apps are supported in incognito.
-  return !is_platform_app() || location() == Manifest::COMPONENT;
+  return IncognitoInfo::IsIncognitoAllowed(this) &&

[not at google - send to devlin, 2015/09/17 22:59:54]

This function has too much logic, especially for one called
can_be_incognito_enabled (supposed to be reserved for simple accessors). Let's
move this to... extension_util.h maybe (in /extensions), as
CanBeIncognitoEnabled, to mirror the IsIncognitoEnabled function (in /chrome).

[Not at Google. Contact bengr, 2015/09/18 21:24:31]

Done.

+         (!is_platform_app() || location() == Manifest::COMPONENT);
 }
 
 void Extension::AddWebExtentPattern(const URLPattern& pattern) {