Clang plugin: Allow >1 WeakPtrFactory member in a class

tools/clang/plugins/tests/weak_ptr_factory.txt

Index: tools/clang/plugins/tests/weak_ptr_factory.txt
diff --git a/tools/clang/plugins/tests/weak_ptr_factory.txt b/tools/clang/plugins/tests/weak_ptr_factory.txt
index f9c2c0a3117516fd6d9164c6e6463a01d31d4089..820b7dbb5a4f96f900988b6155d7417c0d9cdcbc 100644
--- a/tools/clang/plugins/tests/weak_ptr_factory.txt
+++ b/tools/clang/plugins/tests/weak_ptr_factory.txt
@@ -1,7 +1,10 @@
-weak_ptr_factory.cpp:35:38: warning: [chromium-style] WeakPtrFactory members which refer to their outer class must be the last member in the outer class definition.
+weak_ptr_factory.cpp:43:38: warning: [chromium-style] WeakPtrFactory members which refer to their outer class must be the last member in the outer class definition.
   base::WeakPtrFactory<FactoryFirst> factory_;
                                      ^
-weak_ptr_factory.cpp:41:39: warning: [chromium-style] WeakPtrFactory members which refer to their outer class must be the last member in the outer class definition.
+weak_ptr_factory.cpp:49:39: warning: [chromium-style] WeakPtrFactory members which refer to their outer class must be the last member in the outer class definition.
   base::WeakPtrFactory<FactoryMiddle> factory_;
                                       ^
-2 warnings generated.
+weak_ptr_factory.cpp:55:44: warning: [chromium-style] WeakPtrFactory members which refer to their outer class must be the last member in the outer class definition.
+  base::WeakPtrFactory<TwoFactoriesOneBad> factory1_;
+                                           ^
+3 warnings generated.