[TTS] Delay instrumentation tests at startup for flakes.

chrome/test/android/javatests/src/org/chromium/chrome/test/ChromeActivityTestCaseBase.java

Index: chrome/test/android/javatests/src/org/chromium/chrome/test/ChromeActivityTestCaseBase.java
diff --git a/chrome/test/android/javatests/src/org/chromium/chrome/test/ChromeActivityTestCaseBase.java b/chrome/test/android/javatests/src/org/chromium/chrome/test/ChromeActivityTestCaseBase.java
index bb4fa79ca6a82c793484942d646035dae9b679af..74997749dc144cf796e901ad130d0f71dae72b66 100644
--- a/chrome/test/android/javatests/src/org/chromium/chrome/test/ChromeActivityTestCaseBase.java
+++ b/chrome/test/android/javatests/src/org/chromium/chrome/test/ChromeActivityTestCaseBase.java
@@ -412,6 +412,17 @@ public abstract class ChromeActivityTestCaseBase<T extends ChromeActivity>
     }
 
     /**
+     * Like {@code #startMainActivityWithURL} except with an initial specified delay.
+     */
+    protected void startMainActivityWithDelay(String url, long delayMs)
+            throws InterruptedException {
+        // There's a problem with immediate startup that causes flakes due to the page not being
+        // ready, so specify a startup-delay of 1000 for legacy behavior.  See crbug.com/635661.
+        Thread.sleep(delayMs);
+        startMainActivityWithURL(url);
+    }
+
+    /**
      * Starts the Main activity and open a blank page.
      * This is faster and less flakyness-prone than starting on the NTP.
      */