Remove tools/clang (this will break things temporarily).

tools/clang/blink_gc_plugin/tests/class_multiple_trace_bases.txt

Index: tools/clang/blink_gc_plugin/tests/class_multiple_trace_bases.txt
diff --git a/tools/clang/blink_gc_plugin/tests/class_multiple_trace_bases.txt b/tools/clang/blink_gc_plugin/tests/class_multiple_trace_bases.txt
deleted file mode 100644
index a8f270bfb6fba143285163d59a851616b7915db8..0000000000000000000000000000000000000000
--- a/tools/clang/blink_gc_plugin/tests/class_multiple_trace_bases.txt
+++ /dev/null
@@ -1,14 +0,0 @@
-In file included from class_multiple_trace_bases.cpp:5:
-./class_multiple_trace_bases.h:22:1: warning: [blink-gc] Class 'Derived' requires a trace method.
-class Derived : public Base, public Mixin {
-^
-./class_multiple_trace_bases.h:22:17: note: [blink-gc] Untraced base class 'Base' declared here:
-class Derived : public Base, public Mixin {
-                ^
-./class_multiple_trace_bases.h:22:30: note: [blink-gc] Untraced base class 'Mixin' declared here:
-class Derived : public Base, public Mixin {
-                             ^
-./class_multiple_trace_bases.h:22:1: warning: [blink-gc] Class 'Derived' which inherits from GarbageCollectedMixin must locally declare and override trace(Visitor*)
-class Derived : public Base, public Mixin {
-^
-2 warnings generated.