Bug 1246279: increase all firefox tests to a timeout of 90m; r=jmaher

testing/taskcluster/tasks/tests/fx_linux64_mochitest_dt.yml

@@ -9,6 +9,8 @@ task:
     name: '[TC] Linux64 mochitest-devtools-chrome M(dt{{chunk}})'
     description: Mochitest devtools-chrome run {{chunk}}
   payload:
+    # these tests take longer than most to complete
+    maxRunTime: 5400
     capabilities:
       devices:
         loopbackVideo: true

testing/taskcluster/tasks/tests/fx_linux64_mochitest_dt_e10s.yml

@@ -3,6 +3,8 @@ $inherits:
   from: 'tasks/tests/fx_desktop_unittest.yml'
 task:
   payload:
+    # these tests take longer than most to complete
+    maxRunTime: 5400
     command:
       - --e10s
     capabilities: