[TTS] Fix long-press tests to allow empty strings.

chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManagerTest.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManagerTest.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManagerTest.java b/chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManagerTest.java
index 2db6fb07f8106484af0cf127a5248cf1c98277fa..7b8c14bc6239c8b00a3ea2f748d120b09230a474 100644
--- a/chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManagerTest.java
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchManagerTest.java
@@ -825,7 +825,7 @@ public class ContextualSearchManagerTest extends ChromeActivityTestCaseBase<Chro
         waitForGestureProcessing();
         waitForPanelToClose();
         assertPanelClosedOrUndefined();
-        assertNull(getSelectedText());
+        assertTrue(TextUtils.isEmpty(getSelectedText()));
     }
 
     /**
@@ -1347,7 +1347,7 @@ public class ContextualSearchManagerTest extends ChromeActivityTestCaseBase<Chro
         clickNode("question-mark");
         waitForGestureProcessing();
         waitForPanelToCloseAndSelectionEmpty();
-        assertNull(getSelectedText());
+        assertTrue(TextUtils.isEmpty(getSelectedText()));
         assertLoadedNoUrl();
     }