Draw web content area correctly on a phantom window for window dragging

ash/wm/workspace/workspace_window_resizer_unittest.cc

Index: ash/wm/workspace/workspace_window_resizer_unittest.cc
diff --git a/ash/wm/workspace/workspace_window_resizer_unittest.cc b/ash/wm/workspace/workspace_window_resizer_unittest.cc
index 72eca4b06ca73666952ed7a40de474e3d42a952d..f5f085f474c6e0a8a81f56559784defd631b4028 100644
--- a/ash/wm/workspace/workspace_window_resizer_unittest.cc
+++ b/ash/wm/workspace/workspace_window_resizer_unittest.cc
@@ -607,6 +607,7 @@ TEST_F(WorkspaceWindowResizerTest, MAYBE_PhantomStyle) {
         resizer->drag_phantom_window_controller_.get();
     ASSERT_TRUE(controller);
     EXPECT_EQ(PhantomWindowController::STYLE_WINDOW, controller->style());
+    EXPECT_EQ(resizer->layer_, controller->layer());
     // |window_| should be opaque since the pointer is still on the primary
     // root window. The phantom should be semi-transparent.
     EXPECT_FLOAT_EQ(1.0f, window_->layer()->opacity());