Add a new test case to LauncherAnimationsFullscreenSearchTest

The current test case examines the smoothness for the transition
of half-visible search to fullscreen search. The new one does
the test of fullscreen app-list to fullscreen search. I think
this would verify the animation smoothness within the app-list
itself very clearly.

With r676512, the performance numbers (on nocturne) are:
LauncherAnimations/LauncherAnimationsFullscreenSearchTest.SearchAfterFullscreen/0:
  Apps.AppListHide.InputLatency:
    64, 64, 64, 64, 64
  Apps.StateTransition.AnimationSmoothness.Close.ClamshellMode:
    93, 86, 86, 86, 86
  Apps.StateTransition.AnimationSmoothness.FullscreenSearch.ClamshellMode:
    39, 33, 33, 33, 26
LauncherAnimations/LauncherAnimationsFullscreenSearchTest.SearchAfterFullscreen/1:
  Apps.AppListHide.InputLatency:
    63, 55, 64, 63, 64
  Apps.StateTransition.AnimationSmoothness.Close.ClamshellMode:
    93, 93, 93, 100, 93
  Apps.StateTransition.AnimationSmoothness.FullscreenSearch.ClamshellMode:
    66, 59, 73, 73, 66

Bug: 961467
Test: runs on nocturne
Change-Id: I0246c63db1a327b55a1ee8f0540609613a9c0a40
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1699211Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Jun Mukai <mukai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#677063}

chrome/browser/ui/ash/launcher_animations_interactive_uitest.cc

@@ -256,6 +256,22 @@ IN_PROC_BROWSER_TEST_P(LauncherAnimationsFullscreenSearchTest, Run) {
                          ash::AppListViewState::kClosed);
 }
 
+IN_PROC_BROWSER_TEST_P(LauncherAnimationsFullscreenSearchTest,
+                       SearchAfterFullscreen) {
+  // Hit shift+search key; it should switch to kPeeking state.
+  SendKeyAndWaitForState(ui::VKEY_BROWSER_SEARCH, true,
+                         ash::AppListViewState::kFullscreenAllApps);
+
+  // Type some query; it should show the search results in fullscreen (i.e.
+  // switching to kFullscreenSearch state).
+  SendKeyAndWaitForState(ui::VKEY_A, false,
+                         ash::AppListViewState::kFullscreenSearch);
+
+  // Search key to close the launcher.
+  SendKeyAndWaitForState(ui::VKEY_BROWSER_SEARCH, false,
+                         ash::AppListViewState::kClosed);
+}
+
 INSTANTIATE_TEST_SUITE_P(LauncherAnimations,
                          LauncherAnimationsFullscreenSearchTest,
                          /*reuse_widget=*/::testing::Bool());