[telemetry] Move tab from RunState to PageState.

tools/perf/measurements/memory_multi_tab.py

Index: tools/perf/measurements/memory_multi_tab.py
diff --git a/tools/perf/measurements/memory_multi_tab.py b/tools/perf/measurements/memory_multi_tab.py
index dacc395fdbbe028c741b3c2267a3d4a9d68a864f..5148213bd4422cba0f6964a635e9da14a8c14e24 100644
--- a/tools/perf/measurements/memory_multi_tab.py
+++ b/tools/perf/measurements/memory_multi_tab.py
@@ -42,8 +42,8 @@ class MemoryMultiTab(page_measurement.PageMeasurement):
     # a high frequency.
     options.AppendExtraBrowserArgs('--memory-metrics')
 
-  def TabForPage(self, page, tab):
-    return tab.browser.tabs.New()
+  def TabForPage(self, page, browser):
+    return browser.tabs.New()
 
   def DidNavigateToPage(self, page, tab):
     # Start measurement on the first tab.
@@ -57,5 +57,5 @@ class MemoryMultiTab(page_measurement.PageMeasurement):
       self._memory_metric.Stop(page, self._first_tab)
       self._memory_metric.AddResults(self._first_tab, results)
 
-  def DidRunTest(self, tab, results):
+  def DidRunTest(self, browser, results):
     self._memory_metric.AddSummaryResults(results)