prune down content_dll change to just the CONTENT_EXPORTS

content/browser/browser_thread.h

Index: content/browser/browser_thread.h
diff --git a/content/browser/browser_thread.h b/content/browser/browser_thread.h
index 3c47fc0cfa609424653a48bf06dc59a2644246c9..2e798973bc8f6b532fda69eaf96aa4c659c94d62 100644
--- a/content/browser/browser_thread.h
+++ b/content/browser/browser_thread.h
@@ -10,6 +10,7 @@
 #include "base/synchronization/lock.h"
 #include "base/task.h"
 #include "base/threading/thread.h"
+#include "content/common/content_export.h"
 
 #if defined(UNIT_TEST)
 #include "base/logging.h"
@@ -39,7 +40,7 @@ class MessageLoopProxy;
 // task is posted to is guaranteed to outlive the current thread, then no locks
 // are used.  You should never need to cache pointers to MessageLoops, since
 // they're not thread safe.
-class BrowserThread : public base::Thread {
+class CONTENT_EXPORT BrowserThread : public base::Thread {
  public:
   // An enumeration of the well-known threads.
   // NOTE: threads must be listed in the order of their life-time, with each