Refactor common unit test code.

src/compiler/graph-unittest.h

Index: src/compiler/graph-unittest.h
diff --git a/src/compiler/graph-unittest.h b/src/compiler/graph-unittest.h
index 96813d0ea8b21ff198f42f0b8e456f4c5ccc62b7..9eb15531d2e390301c055b2fb6d1dded00c6e373 100644
--- a/src/compiler/graph-unittest.h
+++ b/src/compiler/graph-unittest.h
@@ -6,9 +6,9 @@
 #define V8_COMPILER_GRAPH_UNITTEST_H_
 
 #include "src/compiler/common-operator.h"
-#include "src/compiler/compiler-unittests.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/machine-operator.h"
+#include "src/test/test-utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 namespace v8 {
@@ -24,7 +24,7 @@ namespace compiler {
 using ::testing::Matcher;
 
 
-class GraphTest : public CompilerTest {
+class GraphTest : public TestWithContext, public TestWithZone {
  public:
   explicit GraphTest(int parameters = 1);
   virtual ~GraphTest();