[heap] Introduce enum of garbage collection reasons.

test/cctest/cctest.cc

Index: test/cctest/cctest.cc
diff --git a/test/cctest/cctest.cc b/test/cctest/cctest.cc
index a850fb9c9e3b28245b26a52ae37f53e6d09467c8..17127ed9ec433c3dc5af8416cbc43a4941b443c0 100644
--- a/test/cctest/cctest.cc
+++ b/test/cctest/cctest.cc
@@ -107,6 +107,18 @@ void CcTest::Run() {
 
 i::Heap* CcTest::heap() { return i_isolate()->heap(); }
 
+void CcTest::CollectGarbage(i::AllocationSpace space) {
+  heap()->CollectGarbage(space, i::GarbageCollectionReason::kTesting);
+}
+
+void CcTest::CollectAllGarbage(int flags) {
+  heap()->CollectAllGarbage(flags, i::GarbageCollectionReason::kTesting);
+}
+
+void CcTest::CollectAllAvailableGarbage() {
+  heap()->CollectAllAvailableGarbage(i::GarbageCollectionReason::kTesting);
+}
+
 v8::base::RandomNumberGenerator* CcTest::random_number_generator() {
   return InitIsolateOnce()->random_number_generator();
 }