Componentization: make symbols visible.

Source/modules/fetch/DataConsumerTee.h

Index: Source/modules/fetch/DataConsumerTee.h
diff --git a/Source/modules/fetch/DataConsumerTee.h b/Source/modules/fetch/DataConsumerTee.h
index 3b2ce73c2ba152da52147656e1097a2ccba33b94..eb2862f462be8b99f677f51cae408a0b810fbc94 100644
--- a/Source/modules/fetch/DataConsumerTee.h
+++ b/Source/modules/fetch/DataConsumerTee.h
@@ -5,6 +5,7 @@
 #ifndef DataConsumerTee_h
 #define DataConsumerTee_h
 
+#include "modules/ModulesExport.h"
 #include "public/platform/WebDataConsumerHandle.h"
 
 #include "wtf/OwnPtr.h"
@@ -14,7 +15,7 @@ namespace blink {
 
 class ExecutionContext;
 
-class DataConsumerTee {
+class MODULES_EXPORT DataConsumerTee {
 public:
     // Create two handles from one. |src| must be a valid unlocked handle.
     static void create(ExecutionContext*, PassOwnPtr<WebDataConsumerHandle> src, OwnPtr<WebDataConsumerHandle>* dest1, OwnPtr<WebDataConsumerHandle>* dest2);