Revert of Revert "win: Make oilpan plugin work better with delayed template parsing."

tools/clang/blink_gc_plugin/Config.h

Index: tools/clang/blink_gc_plugin/Config.h
diff --git a/tools/clang/blink_gc_plugin/Config.h b/tools/clang/blink_gc_plugin/Config.h
index 02cbee9a922dc3671c9ff850c83bdd1f50315c75..445952a7cbc929f7e21a81e276c336db5e1d86dd 100644
--- a/tools/clang/blink_gc_plugin/Config.h
+++ b/tools/clang/blink_gc_plugin/Config.h
@@ -214,7 +214,7 @@ class Config {
     TRACE_AFTER_DISPATCH_IMPL_METHOD
   };
 
-  static TraceMethodType GetTraceMethodType(clang::FunctionDecl* method) {
+  static TraceMethodType GetTraceMethodType(const clang::FunctionDecl* method) {
     if (method->getNumParams() != 1)
       return NOT_TRACE_METHOD;
 
@@ -244,7 +244,7 @@ class Config {
     return NOT_TRACE_METHOD;
   }
 
-  static bool IsTraceMethod(clang::FunctionDecl* method) {
+  static bool IsTraceMethod(const clang::FunctionDecl* method) {
     return GetTraceMethodType(method) != NOT_TRACE_METHOD;
   }