Update selection region style

ash/utility/screenshot_controller_unittest.cc

Index: ash/utility/screenshot_controller_unittest.cc
diff --git a/ash/utility/screenshot_controller_unittest.cc b/ash/utility/screenshot_controller_unittest.cc
index 153cf1e161586e9e5ee4f0aef4356bafc1be31c3..faab2a08a11bd690c3ac5658f68c185c7802ff93 100644
--- a/ash/utility/screenshot_controller_unittest.cc
+++ b/ash/utility/screenshot_controller_unittest.cc
@@ -221,6 +221,11 @@ TEST_F(PartialScreenshotControllerTest, VisibilityTest) {
   EXPECT_TRUE(IsActive());
   EXPECT_TRUE(client->IsCursorVisible());
 
+  // Platform's Cursor should be hidden while dragging.
+  GetEventGenerator().PressLeftButton();
+  EXPECT_TRUE(IsActive());
+  EXPECT_FALSE(client->IsCursorVisible());
+
   Cancel();
   EXPECT_TRUE(client->IsCursorVisible());
 }