Proof of concept for running extension API stack through dev tools.

tools/telemetry/telemetry/browser_backend.py

Index: tools/telemetry/telemetry/browser_backend.py
diff --git a/tools/telemetry/telemetry/browser_backend.py b/tools/telemetry/telemetry/browser_backend.py
index b45919dd237c2d5c92e5d358f6f05432512e7a6e..7b69e9f266451e41cd785ffbcb888e6bd4ee470c 100644
--- a/tools/telemetry/telemetry/browser_backend.py
+++ b/tools/telemetry/telemetry/browser_backend.py
@@ -7,6 +7,7 @@ import socket
 import json
 
 from telemetry import browser_gone_exception
+from telemetry import extension_page
 from telemetry import inspector_backend
 from telemetry import tab
 from telemetry import user_agent
@@ -65,6 +66,14 @@ class BrowserBackend(object):
   def _debugger_url(self):
     return 'http://localhost:%i/json' % self._port
 
+  def _ListExtensionPages(self, extension_id, timeout=None):
+    req = urllib2.urlopen(self._debugger_url, timeout=timeout)
+    data = req.read()
+    all_contexts = json.loads(data)
+    pages = [ctx for ctx in all_contexts
+             if ctx['url'].startswith('chrome-extension://%s' % extension_id)]
+    return pages
+
   def _ListTabs(self, timeout=None):
     req = urllib2.urlopen(self._debugger_url, timeout=timeout)
     data = req.read()
@@ -102,6 +111,11 @@ class BrowserBackend(object):
   def GetNthTabUrl(self, index):
     return self._ListTabs()[index]['url']
 
+  def ConnectToExtensionPage(self, browser, extension_id):
+    ib = inspector_backend.InspectorBackend(self,
+        self._ListExtensionPages(extension_id)[0])
+    return extension_page.ExtensionPage(browser, ib)
+
   def ConnectToNthTab(self, browser, index):
     ib = inspector_backend.InspectorBackend(self, self._ListTabs()[index])
     return tab.Tab(browser, ib)