Add IDs to Telemetry Pages.

For outputting Telemtry results as JSON, we will want to be able to refer to a
Page by an ID that uniquely identifies it within a page set. This CL puts that
machinery in place.

R=nduca, dtu
BUG=375541

Review URL: https://codereview.chromium.org/384483002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@282178 0039d316-1c4b-4281-b951-d872f2087c98

tools/telemetry/telemetry/page/page.py

@@ -7,8 +7,10 @@ import os
 import re
 import urlparse
 
+_next_page_id = 0
 
 class Page(object):
+
   def __init__(self, url, page_set=None, base_dir=None, name=''):
     self._url = url
     self._page_set = page_set
@@ -19,6 +21,10 @@ class Page(object):
     self._base_dir = base_dir
     self._name = name
 
+    global _next_page_id
+    self._id = _next_page_id
+    _next_page_id += 1
+
     # These attributes can be set dynamically by the page.
     self.synthetic_delays = dict()
     self.startup_url = page_set.startup_url if page_set else ''
@@ -63,6 +69,10 @@ class Page(object):
   def url(self):
     return self._url
 
+  @property
+  def id(self):
+    return self._id
+
   def GetSyntheticDelayCategories(self):
     result = []
     for delay, options in self.synthetic_delays.items():

tools/telemetry/telemetry/page/page_unittest.py

@@ -115,3 +115,8 @@ class TestPage(unittest.TestCase):
     ps.AddPageWithDefaultRunNavigate('file://../../otherdir/foo')
 
     self.assertEquals(ps[0].display_name, 'foo')
+
+  def testPagesHaveDifferentIds(self):
+    p = page.Page("http://example.com")
+    p2 = page.Page("http://example.com")
+    self.assertNotEqual(p.id, p2.id)