[Telemetry] Move supports_tab_control to PossibleBrowser.

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

Index: tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py
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 c350b24914c61b6b21a35bcc77a43f4bdd68cadf..ff7ddc9d569ebcfc4b8f7efc30e9ec128720c209 100644
--- a/tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py
+++ b/tools/telemetry/telemetry/core/backends/chrome/chrome_browser_backend.py
@@ -33,15 +33,15 @@ class ChromeBrowserBackend(browser_backend.BrowserBackend):
   once a remote-debugger port has been established."""
   # It is OK to have abstract methods. pylint: disable=W0223
 
-  def __init__(self, is_content_shell, supports_extensions, browser_options,
+  def __init__(self, supports_tab_control, supports_extensions, browser_options,
                output_profile_path, extensions_to_load):
     super(ChromeBrowserBackend, self).__init__(
-        is_content_shell=is_content_shell,
         supports_extensions=supports_extensions,
         browser_options=browser_options,
         tab_list_backend=tab_list_backend.TabListBackend)
     self._port = None
 
+    self._supports_tab_control = supports_tab_control
     self._inspector_protocol_version = 0
     self._chrome_branch_number = None
     self._tracing_backend = None
@@ -257,11 +257,11 @@ class ChromeBrowserBackend(browser_backend.BrowserBackend):
 
   @property
   def supports_tab_control(self):
-    return self.chrome_branch_number >= 1303

[achuithb, 2014/06/25 06:55:49]

Awesome! I believe this fixes http://crbug.com/351893

+    return self._supports_tab_control
 
   @property
   def supports_tracing(self):
-    return self.is_content_shell or self.chrome_branch_number >= 1385
+    return True
 
   def StartTracing(self, custom_categories=None,
                    timeout=web_contents.DEFAULT_WEB_CONTENTS_TIMEOUT):