internal,content: remove sticky-header experiment

Change-Id: Icc26f100891db74d6ab19062bad0420a03a52fb6
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/307349
Trust: Jamal Carvalho <jamal@golang.org>
Run-TryBot: Jamal Carvalho <jamal@golang.org>
Reviewed-by: Julie Qiu <julie@golang.org>
diff --git a/content/static/html/helpers/_unit_header.tmpl b/content/static/html/helpers/_unit_header.tmpl
index 1f73d26..1e5b2fe 100644
--- a/content/static/html/helpers/_unit_header.tmpl
+++ b/content/static/html/helpers/_unit_header.tmpl
@@ -196,7 +196,7 @@
       <span class="Site-margin UnitHeader-bannerContent">
         <img height="19px" width="16px" class="UnitHeader-banner-icon" src="/static/img/pkg-icon-info_19x16.svg" alt="">
         <span>
-        Redirected from <span>{{.}}</span>.
+        Redirected from <span data-test-id="redirected-banner-text">{{.}}</span>.
         </span>
       </span>
     </div>
diff --git a/content/static/html/pages/unit.tmpl b/content/static/html/pages/unit.tmpl
index 4ccab83..9f61f6f 100644
--- a/content/static/html/pages/unit.tmpl
+++ b/content/static/html/pages/unit.tmpl
@@ -12,12 +12,7 @@
 
 {{define "main_content"}}
   <div class="Container">
-    {{if (.Experiments.IsActive "sticky-header")}} 
-      {{block "unit_header" .}}{{end}}
-    {{else}}
-      {{block "legacy_unit_header" .}}{{end}}
-      {{block "unit_fixed_header" .}}{{end}}
-    {{end}}
+    {{block "unit_header" .}}{{end}}
     {{block "unit_content" .}}{{end}}
   </div>
 
diff --git a/internal/experiment.go b/internal/experiment.go
index 8ad80e8..fba5c0d 100644
--- a/internal/experiment.go
+++ b/internal/experiment.go
@@ -8,7 +8,6 @@
 const (
 	ExperimentInsertSymbols             = "insert-symbols"
 	ExperimentRetractions               = "retractions"
-	ExperimentStickyHeader					    = "sticky-header"
 	ExperimentSymbolHistoryVersionsPage = "symbol-history-versions-page"
 	ExperimentSymbolHistoryMainPage     = "symbol-history-main-page"
 	ExperimentUnitMetaWithLatest        = "unit-meta-with-latest"
@@ -19,7 +18,6 @@
 var Experiments = map[string]string{
 	ExperimentInsertSymbols:             "Insert data into symbols, package_symbols, and documentation_symbols.",
 	ExperimentRetractions:               "Retrieve and display retraction and deprecation information.",
-	ExperimentStickyHeader:              "Enable the sticky header on the unit page.",
 	ExperimentSymbolHistoryVersionsPage: "Show package API history on the versions page.",
 	ExperimentSymbolHistoryMainPage:     "Show package API history on the main unit page.",
 	ExperimentUnitMetaWithLatest:        "Use latest-version information for GetUnitMeta.",
diff --git a/internal/frontend/server_test.go b/internal/frontend/server_test.go
index 403d924..38c47a5 100644
--- a/internal/frontend/server_test.go
+++ b/internal/frontend/server_test.go
@@ -1152,7 +1152,6 @@
 			testCasesFunc: func() []serverTestCase {
 				return append(serverTestCases(), linksTestCases...)
 			},
-			experiments: []string{internal.ExperimentStickyHeader},
 		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
@@ -1390,7 +1389,7 @@
 				r.AddCookie(c)
 				w = httptest.NewRecorder()
 				handler.ServeHTTP(w, r)
-				err = checkBody(w.Result().Body, in(".LegacyUnitHeader-redirectedFromBanner", hasText(val)))
+				err = checkBody(w.Result().Body, in(`[data-test-id="redirected-banner-text"]`, hasText(val)))
 				if err != nil {
 					t.Fatal(err)
 				}
@@ -1399,7 +1398,7 @@
 				r = httptest.NewRequest("GET", loc, nil)
 				w = httptest.NewRecorder()
 				handler.ServeHTTP(w, r)
-				err = checkBody(w.Result().Body, notIn(".LegacyUnitHeader-redirectedFromBanner"))
+				err = checkBody(w.Result().Body, notIn(`[data-test-id="redirected-banner-text"]`))
 				if err != nil {
 					t.Fatal(err)
 				}
diff --git a/internal/testing/integration/integration_test.go b/internal/testing/integration/integration_test.go
index 064ab0f..52b7158 100644
--- a/internal/testing/integration/integration_test.go
+++ b/internal/testing/integration/integration_test.go
@@ -78,8 +78,8 @@
 		{"example.com/single", "This is the README"},
 		{"example.com/single/pkg", "hello"},
 		{"example.com/single@v1.0.0/pkg", "hello"},
-		{"example.com/deprecated", "LegacyUnitHeader-deprecatedBanner"},
-		{"example.com/retractions@v1.1.0", "LegacyUnitHeader-retractedBanner"},
+		{"example.com/deprecated", "UnitHeader-banner--deprecated"},
+		{"example.com/retractions@v1.1.0", "UnitHeader-banner--retracted"},
 		{"example.com/deprecated?tab=versions", "Deprecated: use something else"},
 		{"example.com/retractions?tab=versions", "Retracted: bad"},
 	} {