CrOS Shelf: Remove gratuitous test expectations

I am not really sure what these expectations are supposed to test.

SKColorTRANSPARENT is defined as R = G = B = A = 0. So GetBaseColor() of
SkColorTRANSPARENT is black.

So what these expectations are testing is basically that the shelf
background target color always gets back to a hardcoded black,
which doesn't seem desirable (that color can change and is defined as
shelf "base color" in shelf_constants.h, this sounds like a
"change detector" test that isn't helping much) and seems very
different from what the test claims to be checking in the first place.

This removes some expectations where they didn't really make sense.

Change-Id: Ic346b0aade25790d3645bb987c8bc483e39ebb6b
Reviewed-on: https://chromium-review.googlesource.com/c/1493084
Commit-Queue: Manu Cornet <manucornet@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636581}

ash/shelf/shelf_background_animator_unittest.cc

@@ -316,40 +316,15 @@ TEST_F(ShelfBackgroundTargetColorTest,
           ->background_animator_for_testing());
 
   NotifySessionStateChanged(session_manager::SessionState::LOGIN_PRIMARY);
-  EXPECT_EQ(GetBaseColor(test_api.shelf_background_target_color()),
-            GetBaseColor(SK_ColorTRANSPARENT));
+  EXPECT_EQ(test_api.shelf_background_target_color(), SK_ColorTRANSPARENT);
 
   SimulateUserLogin("user1@test.com");
 
-  NotifySessionStateChanged(
-      session_manager::SessionState::LOGGED_IN_NOT_ACTIVE);
-  EXPECT_EQ(GetBaseColor(test_api.shelf_background_target_color()),
-            GetBaseColor(SK_ColorTRANSPARENT));
-
   // The shelf has a non-transparent background only when session state is
   // active.
   NotifySessionStateChanged(session_manager::SessionState::ACTIVE);
   EXPECT_EQ(GetBaseColor(test_api.shelf_background_target_color()),
             GetBaseColor(kShelfDefaultBaseColor));
-
-  NotifySessionStateChanged(session_manager::SessionState::LOCKED);
-  EXPECT_EQ(GetBaseColor(test_api.shelf_background_target_color()),
-            GetBaseColor(SK_ColorTRANSPARENT));
-
-  // Ensure the shelf background color is correct after unlocking.
-  NotifySessionStateChanged(session_manager::SessionState::ACTIVE);
-  EXPECT_EQ(GetBaseColor(test_api.shelf_background_target_color()),
-            GetBaseColor(kShelfDefaultBaseColor));
-
-  NotifySessionStateChanged(session_manager::SessionState::LOGIN_SECONDARY);
-  EXPECT_EQ(GetBaseColor(test_api.shelf_background_target_color()),
-            GetBaseColor(SK_ColorTRANSPARENT));
-
-  // Ensure the shelf background color is correct after closing the user adding
-  // screen.
-  NotifySessionStateChanged(session_manager::SessionState::ACTIVE);
-  EXPECT_EQ(GetBaseColor(test_api.shelf_background_target_color()),
-            GetBaseColor(kShelfDefaultBaseColor));
 }
 
 // Verify the target colors of the shelf and item backgrounds are updated based
@@ -366,15 +341,13 @@ TEST_F(ShelfBackgroundTargetColorTest,
           ->background_animator_for_testing());
 
   NotifySessionStateChanged(session_manager::SessionState::OOBE);
-  EXPECT_EQ(GetBaseColor(test_api.shelf_background_target_color()),
-            GetBaseColor(SK_ColorTRANSPARENT));
+  EXPECT_EQ(test_api.shelf_background_target_color(), SK_ColorTRANSPARENT);
 
   SimulateUserLogin("user1@test.com");
 
   NotifySessionStateChanged(
       session_manager::SessionState::LOGGED_IN_NOT_ACTIVE);
-  EXPECT_EQ(GetBaseColor(test_api.shelf_background_target_color()),
-            GetBaseColor(SK_ColorTRANSPARENT));
+  EXPECT_EQ(test_api.shelf_background_target_color(), SK_ColorTRANSPARENT);
 
   NotifySessionStateChanged(session_manager::SessionState::ACTIVE);
   EXPECT_EQ(GetBaseColor(test_api.shelf_background_target_color()),