Remove duplicate unit test

This unit test is redundant with
VirtualKeyboardRootWindowControllerTest_FollowInputFocus which uses a
test DisplayManager utility to properly mock the displays.

The problem with the ui/keyboard unit test is that it simply mocks
windows and treats them as root windows. I'll be following this CL up
with more changes that use displays instead of just root windows and
if this isn't removed, it will start failing.

Change-Id: I20b5c8dfb947211161b7cd761390bc8a76229370
Reviewed-on: https://chromium-review.googlesource.com/991893Reviewed-by: Yuichiro Hanada <yhanada@chromium.org>
Commit-Queue: Blake O'Hare <blakeo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#547914}

ui/keyboard/keyboard_controller_unittest.cc

@@ -385,45 +385,6 @@ TEST_F(KeyboardControllerTest, KeyboardSize) {
   VerifyKeyboardWindowSize(container, keyboard);
 }
 
-// Flaky on Windows. See http://crbug.com/757044
-#if defined(OS_WIN)
-#define MAYBE_KeyboardSizeMultiRootWindow DISABLED_KeyboardSizeMultiRootWindow
-#else
-#define MAYBE_KeyboardSizeMultiRootWindow KeyboardSizeMultiRootWindow
-#endif
-
-TEST_F(KeyboardControllerTest, MAYBE_KeyboardSizeMultiRootWindow) {
-  aura::Window* container(controller()->GetContainerWindow());
-  aura::Window* keyboard(ui()->GetContentsWindow());
-  gfx::Rect screen_bounds = root_window()->bounds();
-  root_window()->AddChild(container);
-  container->AddChild(keyboard);
-  const gfx::Rect& initial_bounds = container->bounds();
-  // The container should be positioned at the bottom of screen and has 0
-  // height.
-  ASSERT_EQ(0, initial_bounds.height());
-  ASSERT_EQ(screen_bounds.height(), initial_bounds.y());
-  VerifyKeyboardWindowSize(container, keyboard);
-
-  // Adding new root window.
-  std::unique_ptr<aura::WindowTreeHost> secondary_tree_host =
-      base::WrapUnique<aura::WindowTreeHost>(
-          aura::WindowTreeHost::Create(gfx::Rect(0, 0, 1000, 500)));
-  secondary_tree_host->InitHost();
-  EXPECT_EQ(1000, secondary_tree_host->window()->bounds().width());
-  EXPECT_EQ(500, secondary_tree_host->window()->bounds().height());
-
-  // Move the keyboard into the secondary root window.
-  controller()->HideKeyboard(
-      KeyboardController::HideReason::HIDE_REASON_AUTOMATIC);
-  root_window()->RemoveChild(container);
-  secondary_tree_host->window()->AddChild(container);
-
-  const gfx::Rect& new_bounds = container->bounds();
-  EXPECT_EQ(500, new_bounds.y());
-  VerifyKeyboardWindowSize(container, keyboard);
-}
-
 // Tests that tapping/clicking inside the keyboard does not give it focus.
 TEST_F(KeyboardControllerTest, ClickDoesNotFocusKeyboard) {
   ScopedAccessibilityKeyboardEnabler scoped_keyboard_enabler;