Mark some AwContentsClientFullScreenTest tests flaky.

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

Index: android_webview/javatests/src/org/chromium/android_webview/test/AwContentsClientFullScreenTest.java
diff --git a/android_webview/javatests/src/org/chromium/android_webview/test/AwContentsClientFullScreenTest.java b/android_webview/javatests/src/org/chromium/android_webview/test/AwContentsClientFullScreenTest.java
index 7cdf7293fef10697bf91080857e6ddc0f2971a18..b2b9d30482c693756858def68e875258178661b9 100644
--- a/android_webview/javatests/src/org/chromium/android_webview/test/AwContentsClientFullScreenTest.java
+++ b/android_webview/javatests/src/org/chromium/android_webview/test/AwContentsClientFullScreenTest.java
@@ -12,6 +12,7 @@
 import org.chromium.android_webview.test.util.JavascriptEventObserver;
 import org.chromium.android_webview.test.util.VideoSurfaceViewUtils;
 import org.chromium.base.test.util.Feature;
+import org.chromium.base.test.util.FlakyTest;
 import org.chromium.content.browser.ContentViewCore;
 import org.chromium.content.browser.test.util.Criteria;
 import org.chromium.content.browser.test.util.CriteriaHelper;
@@ -163,6 +164,7 @@ public boolean onKey(View v, int keyCode, KeyEvent event) {
 
     @MediumTest
     @Feature({"AndroidWebView"})
+    @FlakyTest
     public void testExitFullscreenEndsIfAppInvokesCallbackFromOnHideCustomView() throws Throwable {
         mContentsClient.setOnHideCustomViewRunnable(new Runnable() {
             @Override
@@ -195,6 +197,7 @@ public void doTestOnShowCustomViewAndPlayWithHtmlControl(String videoTestUrl) th
 
     @MediumTest
     @Feature({"AndroidWebView"})
+    @FlakyTest
     public void testHolePunchingSurfaceNotCreatedForClearVideo()
             throws Throwable {
         loadTestPage(VIDEO_TEST_URL);
@@ -245,6 +248,7 @@ public void run() {
 
     @MediumTest
     @Feature({"AndroidWebView"})
+    @FlakyTest
     public void testOnShowCustomViewRemovesHolePunchingSurfaceForVideo()
             throws Throwable {
         getInstrumentation().runOnMainSync(new Runnable() {