Revert of Removing browser.Start() and instead starts the browser at the point...

Revert of Removing browser.Start() and instead starts the browser at the point of creation. (patchset #6 id:120001 of https://codereview.chromium.org/565803002/)

Reason for revert:
investigate build error

Original issue's description:
> Removing browser.Start() and instead starts the browser at the point of creation.
>
> BUG=412126
>
> Committed: https://crrev.com/01c68e8765254d9971296b291ff718b4f6af3004
> Cr-Commit-Position: refs/heads/master@{#295591}
>
> Committed: https://crrev.com/74c6ef17a08754abadb6fb64da14249898285fa8
> Cr-Commit-Position: refs/heads/master@{#296107}

TBR=nednguyen@google.com,slamm@chromium.org,slamm@google.com
NOTREECHECKS=true
NOTRY=true
BUG=412126

Review URL: https://codereview.chromium.org/601473002

Cr-Commit-Position: refs/heads/master@{#296247}

tools/telemetry/telemetry/core/backends/chrome/android_browser_finder.py

@@ -113,12 +113,7 @@ class PossibleAndroidBrowser(possible_browser.PossibleBrowser):
         output_profile_path=self.finder_options.output_profile_path,
         extensions_to_load=self.finder_options.extensions_to_load,
         target_arch=self.finder_options.target_arch)
-    b = browser.Browser(backend,
-                        self._platform_backend,
-                        self._archive_path,
-                        self._append_to_existing_wpr,
-                        self._make_javascript_deterministic,
-                        self._credentials_path)
+    b = browser.Browser(backend, self._platform_backend)
     return b
 
   def SupportsOptions(self, finder_options):

tools/telemetry/telemetry/core/backends/chrome/cros_browser_finder.py

@@ -50,12 +50,7 @@ class PossibleCrOSBrowser(possible_browser.PossibleBrowser):
     if browser_options.create_browser_with_oobe:
       return cros_browser_with_oobe.CrOSBrowserWithOOBE(
           backend, self._platform_backend)
-    return browser.Browser(backend,
-                           self._platform_backend,
-                           self._archive_path,
-                           self._append_to_existing_wpr,
-                           self._make_javascript_deterministic,
-                           self._credentials_path)
+    return browser.Browser(backend, self._platform_backend)
 
   def SupportsOptions(self, finder_options):
     if (len(finder_options.extensions_to_load) != 0) and self._is_guest:

tools/telemetry/telemetry/core/backends/chrome/cros_browser_with_oobe.py

@@ -8,16 +8,9 @@ from telemetry.core.backends.chrome import cros_browser_backend
 
 class CrOSBrowserWithOOBE(browser.Browser):
   """Cros-specific browser."""
-  def __init__(self, backend, platform_backend, archive_path,
-               append_to_existing_wpr, make_javascript_deterministic,
-               credentials_path):
+  def __init__(self, backend, platform_backend):
     assert isinstance(backend, cros_browser_backend.CrOSBrowserBackend)
-    super(CrOSBrowserWithOOBE, self).__init__(backend,
-                                              platform_backend,
-                                              archive_path,
-                                              append_to_existing_wpr,
-                                              make_javascript_deterministic,
-                                              credentials_path)
+    super(CrOSBrowserWithOOBE, self).__init__(backend, platform_backend)
 
   @property
   def oobe(self):

tools/telemetry/telemetry/core/backends/chrome/desktop_browser_finder.py

@@ -60,12 +60,7 @@ class PossibleDesktopBrowser(possible_browser.PossibleBrowser):
         self._flash_path, self._is_content_shell, self._browser_directory,
         output_profile_path=self.finder_options.output_profile_path,
         extensions_to_load=self.finder_options.extensions_to_load)
-    return browser.Browser(backend,
-                           self._platform_backend,
-                           self._archive_path,
-                           self._append_to_existing_wpr,
-                           self._make_javascript_deterministic,
-                           self._credentials_path)
+    return browser.Browser(backend, self._platform_backend)
 
   def SupportsOptions(self, finder_options):
     if (len(finder_options.extensions_to_load) != 0) and self._is_content_shell:

tools/telemetry/telemetry/core/backends/chrome/ios_browser_finder.py

@@ -35,12 +35,7 @@ class PossibleIOSBrowser(possible_browser.PossibleBrowser):
   def Create(self):
     backend = ios_browser_backend.IosBrowserBackend(
         self.finder_options.browser_options)
-    return browser.Browser(backend,
-                           self._platform_backend,
-                           self._archive_path,
-                           self._append_to_existing_wpr,
-                           self._make_javascript_deterministic,
-                           self._credentials_path)
+    return browser.Browser(backend, self._platform_backend)
 
   def SupportsOptions(self, finder_options):
     #TODO(baxley): Implement me.

tools/telemetry/telemetry/core/backends/webdriver/webdriver_desktop_browser_finder.py

@@ -49,12 +49,7 @@ class PossibleWebDriverBrowser(possible_browser.PossibleBrowser):
   def Create(self):
     self._InitPlatformIfNeeded()
     backend = self.CreateWebDriverBackend(self._platform_backend)
-    return browser.Browser(backend,
-                           self._platform_backend,
-                           self._archive_path,
-                           self._append_to_existing_wpr,
-                           self._make_javascript_deterministic,
-                           self._credentials_path)
+    return browser.Browser(backend, self._platform_backend)
 
   def SupportsOptions(self, finder_options):
     if len(finder_options.extensions_to_load) != 0:

tools/telemetry/telemetry/core/browser.py

@@ -27,9 +27,7 @@ class Browser(object):
     with browser_to_create.Create() as browser:
       ... do all your operations on browser here
   """
-  def __init__(self, backend, platform_backend, archive_path,
-               append_to_existing_wpr, make_javascript_deterministic,
-               credentials_path):
+  def __init__(self, backend, platform_backend):
     assert platform_backend.platform != None
 
     self._browser_backend = backend
@@ -38,29 +36,10 @@ class Browser(object):
     self._local_server_controller = local_server.LocalServerController(backend)
     self._tabs = tab_list.TabList(backend.tab_list_backend)
     self.credentials = browser_credentials.BrowserCredentials()
-    self.credentials.credentials_path = credentials_path
     self._platform_backend.DidCreateBrowser(self, self._browser_backend)
 
-    self.SetReplayArchivePath(archive_path,
-                              append_to_existing_wpr,
-                              make_javascript_deterministic)
-
-    browser_options = self._browser_backend.browser_options
-    self.platform.FlushDnsCache()
-    if browser_options.clear_sytem_cache_for_browser_and_profile_on_start:
-      if self.platform.CanFlushIndividualFilesFromSystemCache():
-        self.platform.FlushSystemCacheForDirectory(
-            self._browser_backend.profile_directory)
-        self.platform.FlushSystemCacheForDirectory(
-            self._browser_backend.browser_directory)
-      else:
-        self.platform.FlushEntireSystemCache()
-
-    self._browser_backend.SetBrowser(self)
-    self._browser_backend.Start()
-    self._platform_backend.DidStartBrowser(self, self._browser_backend)
-
   def __enter__(self):
+    self.Start()
     return self
 
   def __exit__(self, *args):
@@ -251,6 +230,22 @@ class Browser(object):
     del result['ProcessCount']
     return result
 
+  def Start(self):
+    browser_options = self._browser_backend.browser_options
+    self.platform.FlushDnsCache()
+    if browser_options.clear_sytem_cache_for_browser_and_profile_on_start:
+      if self.platform.CanFlushIndividualFilesFromSystemCache():
+        self.platform.FlushSystemCacheForDirectory(
+            self._browser_backend.profile_directory)
+        self.platform.FlushSystemCacheForDirectory(
+            self._browser_backend.browser_directory)
+      else:
+        self.platform.FlushEntireSystemCache()
+
+    self._browser_backend.SetBrowser(self)
+    self._browser_backend.Start()
+    self._platform_backend.DidStartBrowser(self, self._browser_backend)
+
   def Close(self):
     """Closes this browser."""
     if self._browser_backend.IsBrowserRunning():

tools/telemetry/telemetry/core/browser_credentials.py

@@ -67,11 +67,11 @@ class BrowserCredentials(object):
     self._backends[credentials_type].LoginNoLongerNeeded(tab)
 
   @property
-  def credentials_path(self):  # pylint: disable=E0202
+  def credentials_path(self):
     return self._credentials_path
 
   @credentials_path.setter
-  def credentials_path(self, credentials_path):  # pylint: disable=E0202
+  def credentials_path(self, credentials_path):
     self._credentials_path = credentials_path
     self._RebuildCredentials()
 

tools/telemetry/telemetry/core/extension_unittest.py

@@ -32,6 +32,7 @@ class ExtensionTest(unittest.TestCase):
       # May not find a browser that supports extensions.
       return False
     self._browser = browser_to_create.Create()
+    self._browser.Start()
     self._extension = self._browser.extensions[load_extension]
     self._extension_id = load_extension.extension_id
     self.assertTrue(self._extension)
@@ -123,6 +124,7 @@ class MultipleExtensionTest(unittest.TestCase):
     # May not find a browser that supports extensions.
     if browser_to_create:
       self._browser = browser_to_create.Create()
+      self._browser.Start()
 
   def tearDown(self):
     if self._browser:

tools/telemetry/telemetry/core/possible_browser.py

@@ -18,10 +18,6 @@ class PossibleBrowser(object):
     self._supports_tab_control = supports_tab_control
     self._platform = None
     self._platform_backend = None
-    self._archive_path = None
-    self._append_to_existing_wpr = False
-    self._make_javascript_deterministic = True
-    self._credentials_path = None
 
   def __repr__(self):
     return 'PossibleBrowser(browser_type=%s)' % self.browser_type
@@ -69,12 +65,3 @@ class PossibleBrowser(object):
 
   def last_modification_time(self):
     return -1
-
-  def SetReplayArchivePath(self, archive_path, append_to_existing_wpr,
-                           make_javascript_deterministic):
-    self._archive_path = archive_path
-    self._append_to_existing_wpr = append_to_existing_wpr
-    self._make_javascript_deterministic = make_javascript_deterministic
-
-  def SetCredentialsPath(self, credentials_path):
-    self._credentials_path = credentials_path

tools/telemetry/telemetry/page/page_runner.py

@@ -45,14 +45,17 @@ class _RunState(object):
     # Create a browser.
     if not self.browser:
       test.CustomizeBrowserOptionsForSinglePage(page, finder_options)
-      possible_browser.SetReplayArchivePath(archive_path,
+      self.browser = possible_browser.Create()
+      self.browser.credentials.credentials_path = credentials_path
+
+      # Set up WPR path on the new browser.
+      self.browser.SetReplayArchivePath(archive_path,
                                         self._append_to_existing_wpr,
                                         page_set.make_javascript_deterministic)
-      possible_browser.SetCredentialsPath(credentials_path)
       self._last_archive_path = page.archive_path
 
       test.WillStartBrowser(possible_browser.platform)
-      self.browser = possible_browser.Create()
+      self.browser.Start()
       test.DidStartBrowser(self.browser)
 
       if self._first_browser:

tools/telemetry/telemetry/unittest/browser_test_case.py

@@ -22,6 +22,7 @@ class BrowserTestCase(unittest.TestCase):
     cls._browser = None
     try:
       cls._browser = browser_to_create.Create()
+      cls._browser.Start()
     except:
       cls.tearDownClass()
       raise