Fix the way browser histograms are obtained

Bug: 961968, 961966, 961962
Change-Id: I1a7b65e2a534231989975fe933397e097251e7af
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1607620
Commit-Queue: rajendrant <rajendrant@chromium.org>
Reviewed-by: Robert Ogden <robertogden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658881}

tools/chrome_proxy/webdriver/lite_page.py

@@ -135,7 +135,7 @@ class LitePage(IntegrationTest):
       test_driver.LoadURL(
         'http://check.googlezip.net/cacheable/test.html?age_seconds=360')
 
-      histogram = test_driver.GetHistogram(
+      histogram = test_driver.GetBrowserHistogram(
         'Previews.StalePreviewTimestampShown')
       self.assertEqual(1, histogram['count'])
       # Check that there is a single entry in the 'Timestamp Shown' bucket.
@@ -147,7 +147,7 @@ class LitePage(IntegrationTest):
       test_driver.LoadURL(
         'http://check.googlezip.net/cacheable/test.html?age_seconds=0')
 
-      histogram = test_driver.GetHistogram(
+      histogram = test_driver.GetBrowserHistogram(
         'Previews.StalePreviewTimestampShown')
       # Check that there is still a single entry in the 'Timestamp Shown'
       # bucket.

tools/chrome_proxy/webdriver/safebrowsing.py

@@ -44,7 +44,7 @@ class SafeBrowsing(IntegrationTest):
       except TimeoutException:
         # Verify that on device safebrowsing records unsafe for mainframe
         # request at bucket=0
-        unsafe_resources = t.GetHistogram('SB2.ResourceTypes2.Unsafe')
+        unsafe_resources = t.GetBrowserHistogram('SB2.ResourceTypes2.Unsafe')
         self.assertEqual(1, unsafe_resources['count'])
         self.assertEqual(1, unsafe_resources['buckets'][0]['count'])
 

tools/chrome_proxy/webdriver/smoke.py

@@ -79,9 +79,9 @@ class Smoke(IntegrationTest):
       t.LoadURL('http://check.googlezip.net/test.html')
       t.SleepUntilHistogramHasEntry("DataReductionProxy.Pingback.Succeeded")
       # Verify one pingback attempt that was successful.
-      attempted = t.GetHistogram('DataReductionProxy.Pingback.Attempted')
+      attempted = t.GetBrowserHistogram('DataReductionProxy.Pingback.Attempted')
       self.assertEqual(1, attempted['count'])
-      succeeded = t.GetHistogram('DataReductionProxy.Pingback.Succeeded')
+      succeeded = t.GetBrowserHistogram('DataReductionProxy.Pingback.Succeeded')
       self.assertEqual(1, succeeded['count'])
 
   # Ensure pageload metric pingback with DataSaver has the variations header.