Deflake AwImeTest

When you click a node, it takes some time before the node can be
focused. This was not properly considered and caused the flakiness.

Test: tried 100+ times on Pixel 2 XL. 50% flakiness --> 0%.
Bug: 990209
Change-Id: I6e209495931b51381c04230cd49ac080674206fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1880371Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Shimi Zhang <ctzsm@chromium.org>
Commit-Queue: Changwan Ryu <changwan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709959}

android_webview/javatests/src/org/chromium/android_webview/test/AwImeTest.java

@@ -254,10 +254,8 @@ public class AwImeTest {
     }
 
     // https://crbug.com/920061
-    // Flaky! - https://crbug.com/990208
     @Test
     @SmallTest
-    @DisabledTest
     public void testFocusAndViewSizeChangeCausesScroll() throws Throwable {
         loadBottomInputHtml();
         Rect currentRect = new Rect();
@@ -279,6 +277,9 @@ public class AwImeTest {
         DOMUtils.clickNode(webContents, "input_text", true /* goThroughAndroidRootView */,
                 false /* shouldScrollIntoView */);
 
+        CriteriaHelper.pollInstrumentationThread(
+                () -> "input_text".equals(DOMUtils.getFocusedNode(webContents)));
+
         TestThreadUtils.runOnUiThreadBlocking(() -> {
             // Expect that we may have a size change.
             ImeAdapter imeAdapter = ImeAdapter.fromWebContents(mTestContainerView.getWebContents());