[VizHitTesting] Enable V2 by default on non-cros

The feature has been run on stable(1%) for over a month and the metrics
are as expected [1]. Turning it on by default on non-cros before pushing
it to 100%.
[1] https://bugs.chromium.org/p/chromium/issues/detail?id=874919#c45

Bug: 874919
Change-Id: I08e4271ae2e12b58f52c47bd25f5326288c0be81
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1856620Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Yi Gu <yigu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705232}

components/viz/common/features.cc

@@ -24,8 +24,13 @@ const base::Feature kVizDisplayCompositor{"VizDisplayCompositor",
                                           base::FEATURE_ENABLED_BY_DEFAULT};
 #endif
 
+#if defined(OS_CHROMEOS)
 const base::Feature kEnableVizHitTestSurfaceLayer{
     "VizHitTestSurfaceLayer", base::FEATURE_DISABLED_BY_DEFAULT};
+#else
+const base::Feature kEnableVizHitTestSurfaceLayer{
+    "VizHitTestSurfaceLayer", base::FEATURE_ENABLED_BY_DEFAULT};
+#endif
 
 // Use Skia's readback API instead of GLRendererCopier.
 const base::Feature kUseSkiaForGLReadback{"UseSkiaForGLReadback",

components/viz/host/hit_test/hit_test_query_unittest.cc

@@ -27,14 +27,17 @@ class HitTestQueryTest : public testing::TestWithParam<bool> {
  protected:
   HitTestQuery& hit_test_query() { return hit_test_query_; }
   void SetUp() override {
-    if (!GetParam()) {
+    if (GetParam()) {
+      feature_list_.InitAndEnableFeature(
+          features::kEnableVizHitTestSurfaceLayer);
+    }
+
+    if (!features::IsVizHitTestingSurfaceLayerEnabled()) {
       // kHitTestIgnore has different meanings in v1 and v2. Some tests set
       // kHitTestIgnore for certain regions which works for v1 but fails v2.
       test_flags_ |= HitTestRegionFlags::kHitTestIgnore;
       return;
     }
-
-    feature_list_.InitAndEnableFeature(features::kEnableVizHitTestSurfaceLayer);
   }
 
   base::test::ScopedFeatureList feature_list_;

testing/variations/fieldtrial_testing_config.json

@@ -6665,11 +6665,7 @@
     "VizHitTest": [
         {
             "platforms": [
-                "android",
-                "chromeos",
-                "linux",
-                "mac",
-                "windows"
+                "chromeos"
             ],
             "experiments": [
                 {