Disable imgur page in v8.browsing_desktop on linux platform

Bug: chromium:788796
Change-Id: I208022746d63a6379dcf55cb12c1ec8fea8aabcc
Reviewed-on: https://chromium-review.googlesource.com/794110Reviewed-by: Juan Antonio Navarro Pérez <perezju@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519740}

tools/perf/benchmarks/v8_browsing.py

@@ -122,6 +122,10 @@ class V8DesktopBrowsingBenchmark(
              'browse:tools:maps',
              [story.expectations.ALL_MAC],
              'crbug.com/773084')
+        self.DisableStory(
+             'browse:media:imgur',
+             [story.expectations.ALL_LINUX],
+             'crbug.com/788796')
     return StoryExpectations()
 
   def SetExtraBrowserOptions(self, options):