Optionally check base classes for refcounting issues

tools/clang/plugins/tests/base_refcounted.txt

 In file included from base_refcounted.cpp:5:
-./base_refcounted.h:45:3: warning: [chromium-style] Classes that are ref-counted should not have public destructors.
+./base_refcounted.h:47:3: warning: [chromium-style] Classes that are ref-counted should not have public destructors.
   ~PublicRefCountedDtorInHeader() {}
   ^
-./base_refcounted.h:57:3: warning: [chromium-style] Classes that are ref-counted should not have public destructors.
+./base_refcounted.h:44:7: note: [chromium-style] 'PublicRefCountedDtorInHeader' inherits from 'base::RefCounted<PublicRefCountedDtorInHeader>' here
+    : public base::RefCounted<PublicRefCountedDtorInHeader> {
+      ^
+./base_refcounted.h:59:3: warning: [chromium-style] Classes that are ref-counted should not have public destructors.
   ~PublicRefCountedThreadSafeDtorInHeader() {}
   ^
-./base_refcounted.h:94:3: warning: [chromium-style] Classes that are ref-counted should not have public destructors.
+./base_refcounted.h:55:7: note: [chromium-style] 'PublicRefCountedThreadSafeDtorInHeader' inherits from 'base::RefCountedThreadSafe<PublicRefCountedThreadSafeDtorInHeader>' here
+    : public base::RefCountedThreadSafe<
+      ^
+./base_refcounted.h:96:3: warning: [chromium-style] Classes that are ref-counted should not have public destructors.
   ~DerivedProtectedToPublicInHeader() {}
   ^
-./base_refcounted.h:99:1: warning: [chromium-style] Classes that are ref-counted should have explicit destructors that are protected or private.
+./base_refcounted.h:93:7: note: [chromium-style] 'DerivedProtectedToPublicInHeader' inherits from 'ProtectedRefCountedDtorInHeader' here
+    : public ProtectedRefCountedDtorInHeader {
+      ^
+./base_refcounted.h:68:7: note: [chromium-style] 'ProtectedRefCountedDtorInHeader' inherits from 'base::RefCounted<ProtectedRefCountedDtorInHeader>' here
+    : public base::RefCounted<ProtectedRefCountedDtorInHeader> {
+      ^
+./base_refcounted.h:101:7: warning: [chromium-style] Classes that are ref-counted should have explicit destructors that are declared protected or private.
 class ImplicitDerivedProtectedToPublicInHeader
-^
+      ^
+./base_refcounted.h:102:7: note: [chromium-style] 'ImplicitDerivedProtectedToPublicInHeader' inherits from 'ProtectedRefCountedDtorInHeader' here
+    : public ProtectedRefCountedDtorInHeader {
+      ^
+./base_refcounted.h:68:7: note: [chromium-style] 'ProtectedRefCountedDtorInHeader' inherits from 'base::RefCounted<ProtectedRefCountedDtorInHeader>' here
+    : public base::RefCounted<ProtectedRefCountedDtorInHeader> {
+      ^
 base_refcounted.cpp:16:3: warning: [chromium-style] Classes that are ref-counted should not have public destructors.
   ~AnonymousDerivedProtectedToPublicInImpl() {}
   ^
+base_refcounted.cpp:13:7: note: [chromium-style] 'AnonymousDerivedProtectedToPublicInImpl' inherits from 'ProtectedRefCountedDtorInHeader' here
+    : public ProtectedRefCountedDtorInHeader {
+      ^
+./base_refcounted.h:68:7: note: [chromium-style] 'ProtectedRefCountedDtorInHeader' inherits from 'base::RefCounted<ProtectedRefCountedDtorInHeader>' here
+    : public base::RefCounted<ProtectedRefCountedDtorInHeader> {
+      ^
 base_refcounted.cpp:26:3: warning: [chromium-style] Classes that are ref-counted should not have public destructors.
   ~PublicRefCountedDtorInImpl() {}
   ^
+base_refcounted.cpp:23:7: note: [chromium-style] 'PublicRefCountedDtorInImpl' inherits from 'base::RefCounted<PublicRefCountedDtorInImpl>' here
+    : public base::RefCounted<PublicRefCountedDtorInImpl> {
+      ^
 base_refcounted.cpp:52:3: warning: [chromium-style] Classes that are ref-counted should not have public destructors.
   ~UnsafeTypedefChainInImpl() {}
   ^
+base_refcounted.cpp:49:34: note: [chromium-style] 'UnsafeTypedefChainInImpl' inherits from 'Baz::MyLocalTypedef' (aka 'RefCounted<Foo::BarInterface>') here
+class UnsafeTypedefChainInImpl : public Baz::MyLocalTypedef {
+                                 ^
 7 warnings generated.