[Telemetry] Partial fix for Telemetry unittests on Android after r283119

tools/telemetry/telemetry/unittest/tab_test_case.py

Index: tools/telemetry/telemetry/unittest/tab_test_case.py
diff --git a/tools/telemetry/telemetry/unittest/tab_test_case.py b/tools/telemetry/telemetry/unittest/tab_test_case.py
index f68a1bcbf3f839b2a97c1119f289dbff919b0ad9..431817d2a918725896aadce898053c49af7c7609 100644
--- a/tools/telemetry/telemetry/unittest/tab_test_case.py
+++ b/tools/telemetry/telemetry/unittest/tab_test_case.py
@@ -40,9 +40,12 @@ class TabTestCase(unittest.TestCase):
       raise
 
   def setUp(self):
-    self._tab = self._browser.tabs.New()
-    while len(self._browser.tabs) > 1:
-      self._browser.tabs[0].Close()
+    if self._browser.supports_tab_control:
+      self._tab = self._browser.tabs.New()
+      while len(self._browser.tabs) > 1:
+        self._browser.tabs[0].Close()
+    else:
+      self._tab = self._browser.tabs[0]
     self._tab.Navigate('about:blank')
     self._tab.WaitForDocumentReadyStateToBeInteractiveOrBetter()