Media Galleries API Scanning: Add Scan Permission and basic test.

chrome/common/extensions/permissions/media_galleries_permission.cc

Index: chrome/common/extensions/permissions/media_galleries_permission.cc
diff --git a/chrome/common/extensions/permissions/media_galleries_permission.cc b/chrome/common/extensions/permissions/media_galleries_permission.cc
index b95777bdcde75236173fc9f0171fafb338ac603d..c3c2769964b9a489aec3591c1bb2e947fe564656 100644
--- a/chrome/common/extensions/permissions/media_galleries_permission.cc
+++ b/chrome/common/extensions/permissions/media_galleries_permission.cc
@@ -31,6 +31,7 @@ namespace extensions {
 
 const char MediaGalleriesPermission::kAllAutoDetectedPermission[] =
     "allAutoDetected";
+const char MediaGalleriesPermission::kScanPermission[] = "scan";
 const char MediaGalleriesPermission::kReadPermission[] = "read";
 const char MediaGalleriesPermission::kCopyToPermission[] = "copyTo";
 const char MediaGalleriesPermission::kDeletePermission[] = "delete";
@@ -55,7 +56,8 @@ bool MediaGalleriesPermission::FromValue(const base::Value* value) {
   bool has_delete = false;
   for (std::set<MediaGalleriesPermissionData>::const_iterator it =
       data_set_.begin(); it != data_set_.end(); ++it) {
-    if (it->permission() == kAllAutoDetectedPermission) {
+    if (it->permission() == kAllAutoDetectedPermission ||
+        it->permission() == kScanPermission) {
       continue;
     }
     if (it->permission() == kReadPermission) {