Enable CrOS/Android DefaultEnableGpuRasterization field trial for bots

testing/variations/fieldtrial_testing_config.json

 {
     "AlternateComponentUrls": [
         {
             "platforms": [
                 "android",
                 "chromeos",
                 "ios",
                 "linux",
                 "mac",
                 "win"
@@ skipping 526 matching lines @@
                         "InfoBarType": "PageAction"
                     }
                 }
             ]
         }
     ],
     "DefaultEnableGpuRasterization": [
         {
             "platforms": [
                 "mac",
-                "win"
+                "win",
+                "chromeos",
+                "android"
             ],
             "experiments": [
                 {
                     "name": "DefaultEnableGpuRasterization",
                     "enable_features": [
                         "DefaultEnableGpuRasterization"
                     ]
                 }
             ]
         }
@@ skipping 2527 matching lines @@
                 {
                     "name": "Enabled",
                     "enable_features": [
                         "use-new-media-cache"
                     ]
                 }
             ]
         }
     ]
 }