Suppress tabs permission warning if there is already a browsingHistory warning.

chrome/common/extensions/permissions/permission_set_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/command_line.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/common/chrome_paths.h"
@@ skipping 793 matching lines @@
   scoped_refptr<PermissionSet> permissions(
       new PermissionSet(api_permissions, ManifestPermissionSet(),
                         URLPatternSet(), URLPatternSet()));
   PermissionMessages messages =
       PermissionMessageProvider::Get()->GetPermissionMessages(
           permissions, Manifest::TYPE_PLATFORM_APP);
   ASSERT_EQ(1u, messages.size());
   EXPECT_EQ(PermissionMessage::kFileSystemWriteDirectory, messages[0].id());
 }
 
+TEST(PermissionsTest, SuppressedPermissionMessages) {
+  APIPermissionSet api_permissions;
+  api_permissions.insert(APIPermission::kTab);
+  api_permissions.insert(APIPermission::kHistory);
+  scoped_refptr<PermissionSet> permissions(
+      new PermissionSet(api_permissions, ManifestPermissionSet(),
+                        URLPatternSet(), URLPatternSet()));
+  PermissionMessages messages =
+      PermissionMessageProvider::Get()->GetPermissionMessages(
+          permissions, Manifest::TYPE_EXTENSION);
+  EXPECT_EQ(1u, messages.size());
+  EXPECT_EQ(PermissionMessage::kBrowsingHistory, messages[0].id());
+}
+
 TEST(PermissionsTest, MergedFileSystemPermissionComparison) {
   APIPermissionSet write_api_permissions;
   write_api_permissions.insert(APIPermission::kFileSystemWrite);
   scoped_refptr<PermissionSet> write_permissions(
       new PermissionSet(write_api_permissions, ManifestPermissionSet(),
                         URLPatternSet(), URLPatternSet()));
 
   APIPermissionSet directory_api_permissions;
   directory_api_permissions.insert(APIPermission::kFileSystemDirectory);
   scoped_refptr<PermissionSet> directory_permissions(
@@ skipping 695 matching lines @@
   scoped_refptr<const PermissionSet> permissions_dwr(
       extension_dwr->GetActivePermissions());
 
   EXPECT_FALSE(PermissionMessageProvider::Get()->
                    IsPrivilegeIncrease(permissions.get(),
                                        permissions_dwr.get(),
                                        extension->GetType()));
 }
 
 }  // namespace extensions