Make unittests work in component build

src/cancelable-task.h

Index: src/cancelable-task.h
diff --git a/src/cancelable-task.h b/src/cancelable-task.h
index 765533d0990322725252dd69fe7e24027670fdf0..9f17bfb9a7326d15b171aa75322d04008b656b09 100644
--- a/src/cancelable-task.h
+++ b/src/cancelable-task.h
@@ -11,6 +11,7 @@
 #include "src/base/atomic-utils.h"
 #include "src/base/macros.h"
 #include "src/base/platform/condition-variable.h"
+#include "src/globals.h"
 
 namespace v8 {
 namespace internal {
@@ -21,7 +22,7 @@ class Isolate;
 
 // Keeps track of cancelable tasks. It is possible to register and remove tasks
 // from any fore- and background task/thread.
-class CancelableTaskManager {
+class V8_EXPORT_PRIVATE CancelableTaskManager {
  public:
   CancelableTaskManager();
 
@@ -67,8 +68,7 @@ class CancelableTaskManager {
   DISALLOW_COPY_AND_ASSIGN(CancelableTaskManager);
 };
 
-
-class Cancelable {
+class V8_EXPORT_PRIVATE Cancelable {
  public:
   explicit Cancelable(CancelableTaskManager* parent);
   virtual ~Cancelable();