[Telemetry] Update facebook credential & reenable memory.top_7_stress

Reland patch from issue 951773002 at patchset 1 (http://crrev.com/951773002#ps1).
Rerecord & upload the wpr file to cloud storage.

To reviewers: to make sure that this doesn't produce the same problem in
https://codereview.chromium.org/952963002/, please wait for
https://codereview.chromium.org/954753002/ to be landed first.

BUG=459646

Review URL: https://codereview.chromium.org/954763002

Cr-Commit-Position: refs/heads/master@{#317975}

tools/perf/benchmarks/memory.py

@@ -17,7 +17,6 @@ class MemoryMobile(benchmark.Benchmark):
     return 'memory.mobile_memory'
 
 
-@benchmark.Disabled  # http://crbug.com/459646
 class MemoryTop7Stress(benchmark.Benchmark):
   """Use (recorded) real world web sites and measure memory consumption."""
   test = memory.Memory

tools/perf/page_sets/data/top_7_stress.json

 {
     "description": "Describes the Web Page Replay archives for a user story set. Don't edit by hand! Use record_wpr for updating.", 
     "archives": {
+        "top_7_stress_004.wpr": [
+            "Facebook"
+        ], 
         "top_7_stress_001.wpr": [
             "https://plus.google.com/110031535020051778989/posts"
         ], 
@@ -10,7 +13,6 @@
             "https://www.google.com/calendar/"
         ], 
         "top_7_stress_002.wpr": [
-            "Facebook", 
             "Blogger", 
             "Wordpress"
         ]

tools/perf/page_sets/data/top_7_stress_004.wpr.sha1

+b668bea1a6d90643841c3eb4b55fbb6e7c855657
\ No newline at end of file

tools/perf/page_sets/top_7_stress.py

@@ -299,10 +299,10 @@ class FacebookPage(Top7StressPage):
 
   def __init__(self, page_set):
     super(FacebookPage, self).__init__(
-      url='http://www.facebook.com/barackobama',
+      url='https://www.facebook.com/barackobama',
       page_set=page_set,
       name='Facebook')
-    self.credentials = 'facebook'
+    self.credentials = 'facebook2'
 
   def RunNavigateSteps(self, action_runner):
     super(FacebookPage, self).RunNavigateSteps(action_runner)