prune down content_dll change to just the CONTENT_EXPORTS

content/browser/trace_controller.h

Index: content/browser/trace_controller.h
diff --git a/content/browser/trace_controller.h b/content/browser/trace_controller.h
index 4c3d9f39d6ccc4a5eacc3dd307c83cd9b7b9d629..1e7d41b65a33e92e846feb6b964f2edd712eef69 100644
--- a/content/browser/trace_controller.h
+++ b/content/browser/trace_controller.h
@@ -13,6 +13,7 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/singleton.h"
 #include "base/task.h"
+#include "content/common/content_export.h"
 
 class TraceMessageFilter;
 
@@ -36,7 +37,7 @@ class TraceSubscriber {
 // trace status and collect trace data. Only the browser UI thread is allowed
 // to interact with the TraceController object. All calls on the TraceSubscriber
 // happen on the UI thread.
-class TraceController {
+class CONTENT_EXPORT TraceController {
  public:
   static TraceController* GetInstance();