Fix a race on cros where a WebSocketException is raised if we navigate too early.

We see this bug with the perf tests because they navigate right away as they are launched.

BUG=324916
TEST=manual

Review URL: https://codereview.chromium.org/105253002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239304 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 29 insertions, 20 deletions

diff --git a/tools/telemetry/telemetry/core/backends/chrome/android_browser_backend.py b/tools/telemetry/telemetry/core/backends/chrome/android_browser_backend.py
index 20a55b1..6d98d36 100644
--- a/tools/telemetry/telemetry/core/backends/chrome/android_browser_backend.py
+++ b/tools/telemetry/telemetry/core/backends/chrome/android_browser_backend.py
@@ -274,6 +274,7 @@ class AndroidBrowserBackend(chrome_browser_backend.ChromeBrowserBackend):
     try:
       self._WaitForBrowserToComeUp()
       self._PostBrowserStartupInitialization()
+      self._WaitForInitialTabNavigation()
     except exceptions.BrowserGoneException:
       logging.critical('Failed to connect to browser.')
       if not self._adb.Adb().CanAccessProtectedFileContents():
diff --git a/tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py b/tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py
index e1fdbb5..0da000f 100644
--- a/tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py
+++ b/tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py
@@ -212,6 +212,10 @@ class ChromeBrowserBackend(browser_backend.BrowserBackend):
     self._inspector_protocol_version = 1.0
     self._chrome_branch_number = 1025
 
+  def _WaitForInitialTabNavigation(self):
+    """Wait for the first tab to finish navigating."""
+    self.tab_list_backend[0].WaitForDocumentReadyStateToBeComplete()
+
   def Request(self, path, timeout=None, throw_network_exception=False):
     url = 'http://127.0.0.1:%i/json' % self._port
     if path:
diff --git a/tools/telemetry/telemetry/core/backends/chrome/cros_browser_backend.py b/tools/telemetry/telemetry/core/backends/chrome/cros_browser_backend.py
index 76921b7..81f945c 100644
--- a/tools/telemetry/telemetry/core/backends/chrome/cros_browser_backend.py
+++ b/tools/telemetry/telemetry/core/backends/chrome/cros_browser_backend.py
@@ -244,10 +244,17 @@ class CrOSBrowserBackend(chrome_browser_backend.ChromeBrowserBackend):
         # Guest browsing shuts down the current browser and launches an
         # incognito browser in a separate process, which we need to wait for.
         util.WaitFor(lambda: pid != self.pid, 10)
-        self._WaitForBrowserToComeUp()
       else:
         self._NavigateLogin()
 
+    try:
+      self._WaitForBrowserToComeUp()
+      self._WaitForInitialTabNavigation()
+    except util.TimeoutException:
+      logging.error('Chrome args: %s' % self._GetChromeProcess()['args'])
+      self._cri.TakeScreenShot('extension-timeout')
+      raise
+
     logging.info('Browser is up!')
 
   def Close(self):
@@ -420,13 +427,21 @@ class CrOSBrowserBackend(chrome_browser_backend.ChromeBrowserBackend):
       # Open a new window/tab.
       self.tab_list_backend.New(15)
 
-    # Wait for extensions to load.
-    try:
-      self._WaitForBrowserToComeUp()
-    except util.TimeoutException:
-      logging.error('Chrome args: %s' % self._GetChromeProcess()['args'])
-      self._cri.TakeScreenShot('extension-timeout')
-      raise
+  def _WaitForInitialTabNavigation(self):
+    """A new tab starts with about:blank and then navigates to the NTP.
+    The debugger_url changes during this navigation, so if we attempt to access
+    the page during this time, we get a WebSocketException/TabCrashException
+    (that the tab doesn't actually crash).
+    """
+    def InitialTabNavigationComplete():
+      try:
+        ret =  self._tab_list_backend[0].url != 'about:blank'
+        if ret:
+          self.tab_list_backend[0].WaitForDocumentReadyStateToBeComplete()
+        return ret
+      except exceptions.TabCrashException:
+        return False
+    util.WaitFor(InitialTabNavigationComplete, timeout=10)
 
 
 class SSHForwarder(object):
diff --git a/tools/telemetry/telemetry/core/backends/chrome/desktop_browser_backend.py b/tools/telemetry/telemetry/core/backends/chrome/desktop_browser_backend.py
index 5f4e3dc..1aa8903 100644
--- a/tools/telemetry/telemetry/core/backends/chrome/desktop_browser_backend.py
+++ b/tools/telemetry/telemetry/core/backends/chrome/desktop_browser_backend.py
@@ -93,6 +93,7 @@ class DesktopBrowserBackend(chrome_browser_backend.ChromeBrowserBackend):
     try:
       self._WaitForBrowserToComeUp()
       self._PostBrowserStartupInitialization()
+      self._WaitForInitialTabNavigation()
     except:
       self.Close()
       raise
diff --git a/tools/telemetry/telemetry/page/page_runner.py b/tools/telemetry/telemetry/page/page_runner.py
index 7d1f024..253bc92 100644
--- a/tools/telemetry/telemetry/page/page_runner.py
+++ b/tools/telemetry/telemetry/page/page_runner.py
@@ -37,7 +37,6 @@ class _RunState(object):
 
   def StartBrowser(self, test, page_set, page, possible_browser,
                    credentials_path, archive_path):
-    started_browser = not self.browser
     # Create a browser.
     if not self.browser:
       self.browser = possible_browser.Create()
@@ -92,17 +91,6 @@ class _RunState(object):
         while len(self.browser.tabs) > 1:
           self.browser.tabs[-1].Close()
 
-      # Must wait for tab to commit otherwise it can commit after the next
-      # navigation has begun and RenderFrameHostManager::DidNavigateMainFrame()
-      # will cancel the next navigation because it's pending. This manifests as
-      # the first navigation in a PageSet freezing indefinitly because the
-      # navigation was silently cancelled when |self.browser.tabs[0]| was
-      # committed. Only do this when we just started the browser, otherwise
-      # there are cases where previous pages in a PageSet never complete
-      # loading so we'll wait forever.
-      if started_browser:
-        self.browser.tabs[0].WaitForDocumentReadyStateToBeComplete()
-
     if self.first_page[page]:
       self.first_page[page] = False