Add unittests for null/empty window shapes

chrome/browser/ui/views/apps/shaped_app_window_targeter_unittest.cc

Index: chrome/browser/ui/views/apps/shaped_app_window_targeter_unittest.cc
diff --git a/chrome/browser/ui/views/apps/shaped_app_window_targeter_unittest.cc b/chrome/browser/ui/views/apps/shaped_app_window_targeter_unittest.cc
index 05c6ae439de748aeed5eeec2db4bc975cb06fce8..0da22577bfd783ca7eb69da2ac81479658add0f7 100644
--- a/chrome/browser/ui/views/apps/shaped_app_window_targeter_unittest.cc
+++ b/chrome/browser/ui/views/apps/shaped_app_window_targeter_unittest.cc
@@ -94,6 +94,28 @@ TEST_F(ShapedAppWindowTargeterTest, HitTestBasic) {
     ASSERT_FALSE(details.dispatcher_destroyed);
     EXPECT_EQ(window, move2.target());
   }
+
+  region.reset(new SkRegion);
+  region->op(SkIRect::MakeXYWH(0, 0, 0, 0), SkRegion::kUnion_Op);
+  app_window()->UpdateShape(region.Pass());
+  {
+    // With an empty custom shape, all events within the window should fall
+    // through to the root window.
+    ui::MouseEvent move(ui::ET_MOUSE_MOVED,

[tapted, 2014/09/29 01:16:20]

This is super-nitty, but I kinda feel this would be more compelling in the first
block; along with the "without any custom shapes" test (i.e. just after it).

`move2` doesn't really add much to this test case. However, if sending the
"same" event before and after adding a custom shape changes the window that it
hits, it's easier to see how adding an empty shape changes the behavior.

Here, I had to look up to the SetUp() function to convince myself whether the
coordinates in the event should result in a hit on the window or not.

[garykac, 2014/09/29 23:50:59]

Moved.
Removed.
It took me a while to figure it out as well (since I didn't write the original
test). I considered adding ASCII art to make it clear what the shape was, but
thought it might be too "heavy".  I added one now, so let me know if you think
it's useful to keep in the cl.

+                        gfx::Point(40, 40), gfx::Point(40, 40),
+                        ui::EF_NONE, ui::EF_NONE);
+    ui::EventDispatchDetails details =
+        event_processor()->OnEventFromSource(&move);
+    ASSERT_FALSE(details.dispatcher_destroyed);
+    EXPECT_EQ(root_window(), move.target());
+
+    ui::MouseEvent move2(ui::ET_MOUSE_MOVED,
+                         gfx::Point(80, 80), gfx::Point(80, 80),
+                         ui::EF_NONE, ui::EF_NONE);
+    details = event_processor()->OnEventFromSource(&move2);
+    ASSERT_FALSE(details.dispatcher_destroyed);
+    EXPECT_EQ(root_window(), move2.target());
+  }
 }
 
 TEST_F(ShapedAppWindowTargeterTest, HitTestOnlyForShapedWindow) {