Refactor frame navigation/detach state cleanup to be more sane.

Source/core/css/MediaQueryEvaluatorTest.cpp

Index: Source/core/css/MediaQueryEvaluatorTest.cpp
diff --git a/Source/core/css/MediaQueryEvaluatorTest.cpp b/Source/core/css/MediaQueryEvaluatorTest.cpp
index 5d1ff47a9c8900c61adeda06390d27fac30b92d2..021e7e353f71ac5a1609050de68116d7e7595fe5 100644
--- a/Source/core/css/MediaQueryEvaluatorTest.cpp
+++ b/Source/core/css/MediaQueryEvaluatorTest.cpp
@@ -152,13 +152,12 @@ TEST(MediaQueryEvaluatorTest, Dynamic)
 TEST(MediaQueryEvaluatorTest, DynamicNoView)
 {
     OwnPtr<DummyPageHolder> pageHolder = DummyPageHolder::create(IntSize(500, 500));
-    RefPtrWillBePersistent<FrameView> view = pageHolder->frame().view();
-    pageHolder->frame().setView(nullptr);
-    MediaQueryEvaluator mediaQueryEvaluator(&pageHolder->frame());
-    RefPtrWillBePersistent<MediaQuerySet> querySet = MediaQuerySet::create("foobar");
-    bool output = false;
-    ASSERT_EQ(output, mediaQueryEvaluator.eval(querySet.get()));
-    pageHolder->frame().setView(view);

[dcheng, 2015/04/03 14:35:45]

Since this test didn't need to flout the invariants about frame state, I
simplified it a bit. This meant I had to remove an ASSERT in DummyPageHolder's
dtor, but I think that's OK: holding references to keep objects alive to test
weird edge cases of frame detach is a legitimate need of unit test code, and
does not indicate a logic error.

+    RefPtrWillBeRawPtr<LocalFrame> frame = &pageHolder->frame();
+    pageHolder.clear();
+    ASSERT_EQ(nullptr, frame->view());
+    MediaQueryEvaluator mediaQueryEvaluator(frame.get());
+    RefPtrWillBeRawPtr<MediaQuerySet> querySet = MediaQuerySet::create("foobar");
+    EXPECT_EQ(false, mediaQueryEvaluator.eval(querySet.get()));
 }
 
 } // namespace