internal: remove experiment use-units

For golang/go#39629

Change-Id: Icdcf8b29a3245ac1e346e1dc22264465145d3828
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/258278
Trust: Julie Qiu <julie@golang.org>
Run-TryBot: Julie Qiu <julie@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
diff --git a/internal/experiment.go b/internal/experiment.go
index e57021b..c5b37dc 100644
--- a/internal/experiment.go
+++ b/internal/experiment.go
@@ -12,7 +12,6 @@
 	ExperimentRemoveUnusedAST     = "remove-unused-ast"
 	ExperimentSidenav             = "sidenav"
 	ExperimentUnitPage            = "unit-page"
-	ExperimentUseUnits            = "use-units"
 )
 
 // Experiments represents all of the active experiments in the codebase and
@@ -24,7 +23,6 @@
 	ExperimentRemoveUnusedAST:     "Prune AST prior to rendering documentation HTML.",
 	ExperimentSidenav:             "Display documentation index on the left sidenav.",
 	ExperimentUnitPage:            "Enable the redesigned details page.",
-	ExperimentUseUnits:            "Read from paths, documentation, readmes, and package_imports tables.",
 }
 
 // Experiment holds data associated with an experimental feature for frontend
diff --git a/internal/frontend/details.go b/internal/frontend/details.go
index dfba6c1..c70269b 100644
--- a/internal/frontend/details.go
+++ b/internal/frontend/details.go
@@ -160,7 +160,7 @@
 			}
 		}()
 	}
-	if isActiveUnitPage(ctx) {
+	if experiment.IsActive(ctx, internal.ExperimentUnitPage) {
 		return s.serveUnitPage(ctx, w, r, ds, um, urlInfo.requestedVersion)
 	}
 	return s.serveDetailsPage(w, r, ds, um, urlInfo)
@@ -344,13 +344,6 @@
 	return requestedVersion == internal.MasterVersion
 }
 
-// isActiveUnitPage reports whether the experiments needed for viewing
-// unit page are active.
-func isActiveUnitPage(ctx context.Context) bool {
-	return experiment.IsActive(ctx, internal.ExperimentUnitPage) &&
-		experiment.IsActive(ctx, internal.ExperimentUseUnits)
-}
-
 // pathNotFoundError returns a page with an option on how to
 // add a package or module to the site.
 func pathNotFoundError(fullPath, requestedVersion string) error {
diff --git a/internal/frontend/search_test.go b/internal/frontend/search_test.go
index 861737d..374e1ee 100644
--- a/internal/frontend/search_test.go
+++ b/internal/frontend/search_test.go
@@ -11,7 +11,6 @@
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 	"golang.org/x/pkgsite/internal"
-	"golang.org/x/pkgsite/internal/experiment"
 	"golang.org/x/pkgsite/internal/licenses"
 	"golang.org/x/pkgsite/internal/postgres"
 	"golang.org/x/pkgsite/internal/testing/sample"
@@ -177,19 +176,9 @@
 }
 
 func TestSearchRequestRedirectPath(t *testing.T) {
-	t.Run("no experiments ", func(t *testing.T) {
-		testSearchRequestRedirectPath(t)
-	})
-	t.Run("use-paths-table", func(t *testing.T) {
-		testSearchRequestRedirectPath(t, internal.ExperimentUseUnits)
-	})
-}
-
-func testSearchRequestRedirectPath(t *testing.T, experimentNames ...string) {
 	// Experiments need to be set in the context, for DB work, and as
 	// a middleware, for request handling.
 	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
-	ctx = experiment.NewContext(ctx, experimentNames...)
 
 	defer cancel()
 	defer postgres.ResetTestDB(testDB, t)
diff --git a/internal/frontend/server_test.go b/internal/frontend/server_test.go
index b25bb96..8fcafe5 100644
--- a/internal/frontend/server_test.go
+++ b/internal/frontend/server_test.go
@@ -892,11 +892,6 @@
 			name:          "no experiments",
 			testCasesFunc: serverTestCases,
 		},
-		{
-			name:          "use directories",
-			testCasesFunc: serverTestCases,
-			experiments:   []string{internal.ExperimentUseUnits},
-		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			testServer(t, test.testCasesFunc(), test.experiments...)