[Telemetry] Fix a possible source of flakiness on Android.

tools/telemetry/telemetry/page_runner.py

Index: tools/telemetry/telemetry/page_runner.py
diff --git a/tools/telemetry/telemetry/page_runner.py b/tools/telemetry/telemetry/page_runner.py
index 7f0ba07f8ccc4eefa5dbe9ae1d17af8f62443d33..11c90dffb78dc310143d3fe1351dff6c4c5fe50c 100644
--- a/tools/telemetry/telemetry/page_runner.py
+++ b/tools/telemetry/telemetry/page_runner.py
@@ -8,6 +8,7 @@ import traceback
 import urlparse
 import random
 
+from telemetry import connection_gone_exception
 from telemetry import page_set_url_builder
 from telemetry import page_test
 from telemetry import tab_crash_exception
@@ -211,6 +212,8 @@ http://goto/read-src-internal, or create a new archive using --record.
       logging.warning('Tab crashed: %s', page.url)
       results.AddFailure(page, ex, traceback.format_exc())
       raise
+    except connection_gone_exception.ConnectionGoneException:
+      raise connection_gone_exception.ConnectionGoneException()
     except Exception, ex:
       logging.error('Unexpected failure while running %s: %s',
                     page.url, traceback.format_exc())
@@ -235,6 +238,8 @@ http://goto/read-src-internal, or create a new archive using --record.
       logging.warning('Tab crashed: %s', page.url)
       results.AddFailure(page, ex, traceback.format_exc())
       raise
+    except connection_gone_exception.ConnectionGoneException:
+      raise connection_gone_exception.ConnectionGoneException()
     except Exception, ex:
       logging.error('Unexpected failure while running %s: %s',
                     page.url, traceback.format_exc())
@@ -289,5 +294,8 @@ http://goto/read-src-internal, or create a new archive using --record.
   def _CleanUpPage(self, page, tab, page_state): # pylint: disable=R0201
     if page.credentials and page_state.did_login:
       tab.browser.credentials.LoginNoLongerNeeded(tab, page.credentials)
-    tab.runtime.Evaluate("""window.chrome && chrome.benchmarking &&
-                            chrome.benchmarking.closeConnections()""")
+    try:
+      tab.runtime.Evaluate("""window.chrome && chrome.benchmarking &&
+                              chrome.benchmarking.closeConnections()""")
+    except Exception:
+      pass