[Tracing] Remove unused excluded categories list.

src/libplatform/tracing/trace-config.cc

Index: src/libplatform/tracing/trace-config.cc
diff --git a/src/libplatform/tracing/trace-config.cc b/src/libplatform/tracing/trace-config.cc
index 7a824f614ed8ae476c4667e829eda7861f96ce74..e77d191e5e1cc32737d205842a1fd80d00e35ebf 100644
--- a/src/libplatform/tracing/trace-config.cc
+++ b/src/libplatform/tracing/trace-config.cc
@@ -32,11 +32,6 @@ void TraceConfig::AddIncludedCategory(const char* included_category) {
   included_categories_.push_back(included_category);
 }
 
-void TraceConfig::AddExcludedCategory(const char* excluded_category) {
-  DCHECK(excluded_category != NULL && strlen(excluded_category) > 0);
-  excluded_categories_.push_back(excluded_category);
-}
-
 }  // namespace tracing
 }  // namespace platform
 }  // namespace v8