[iOS] Create a flag for the new experimental omnibox implementation.

This flag will guard a new implementation of OmniboxTextFieldIOS

Bug: None
Change-Id: I305e0d980287950595fd591e8dc71be34f141b80
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2611244
Commit-Queue: Stepan Khapugin <stkhapugin@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841020}

chrome/browser/flag-metadata.json

@@ -3647,6 +3647,11 @@
     "owners": [ "ender", "chrome-omnibox-team@google.com" ],
     "expiry_milestone": 93
   },
+  {
+      "name": "omnibox-new-textfield-implementation",
+      "owners": ["stkhapugin", "rkgibson@google.com", "chrome-omnibox-team@google.com"],
+      "expiry_milestone": 95
+  },
   {
     "name": "omnibox-on-device-head-suggestions-incognito",
     "owners": [ "cechen", "suggest-2g@google.com" ],

ios/chrome/browser/flags/about_flags.mm

@@ -595,6 +595,10 @@ const flags_ui::FeatureEntry kFeatureEntries[] = {
      flags_ui::kOsIos,
      FEATURE_VALUE_TYPE(
          password_manager::features::kUseOfHashAffiliationFetcher)},
+    {"omnibox-new-textfield-implementation",
+     flag_descriptions::kOmniboxNewImplementationName,
+     flag_descriptions::kOmniboxNewImplementationDescription, flags_ui::kOsIos,
+     FEATURE_VALUE_TYPE(kIOSNewOmniboxImplementation)},
 };
 
 bool SkipConditionalFeatureEntry(const flags_ui::FeatureEntry& entry) {

ios/chrome/browser/flags/ios_chrome_flag_descriptions.cc

@@ -336,6 +336,11 @@ const char kOmniboxLocalHistoryZeroSuggestDescription[] =
     "Configures the omnibox zero-prefix suggestion to use local search "
     "history.";
 
+const char kOmniboxNewImplementationName[] =
+    "Use experimental omnibox textfield";
+const char kOmniboxNewImplementationDescription[] =
+    "Uses a textfield implementation that doesn't use UILabels internally";
+
 const char kRefactoredNTPName[] = "Enables refactored new tab page";
 const char kRefactoredNTPDescription[] =
     "When enabled, the new tab page is replaced with the refactored version, "

ios/chrome/browser/flags/ios_chrome_flag_descriptions.h

@@ -292,6 +292,11 @@ extern const char kOmniboxOnFocusSuggestionsDescription[];
 extern const char kOmniboxLocalHistoryZeroSuggestName[];
 extern const char kOmniboxLocalHistoryZeroSuggestDescription[];
 
+// Title and description for the flag to swap Omnibox Textfield implementation
+// to a new experimental one.
+extern const char kOmniboxNewImplementationName[];
+extern const char kOmniboxNewImplementationDescription[];
+
 // Title and description for the flag that enables the refactored new tab page.
 extern const char kRefactoredNTPName[];
 extern const char kRefactoredNTPDescription[];

ios/chrome/browser/ui/ui_feature_flags.cc

@@ -67,5 +67,8 @@ const base::Feature kDefaultBrowserFullscreenPromoExperiment{
 const base::Feature kIOSSharedHighlightingColorChange{
     "IOSSharedHighlightingColorChange", base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kIOSNewOmniboxImplementation{
+    "kIOSNewOmniboxImplementation", base::FEATURE_DISABLED_BY_DEFAULT};
+
 const base::Feature kIOSPersistCrashRestore{"IOSPersistCrashRestore",
                                             base::FEATURE_DISABLED_BY_DEFAULT};

ios/chrome/browser/ui/ui_feature_flags.h

@@ -71,6 +71,9 @@ extern const base::Feature kDefaultBrowserFullscreenPromoExperiment;
 // Feature flag that enable Shared Highlighting color change in iOS.
 extern const base::Feature kIOSSharedHighlightingColorChange;
 
+// Feature flag that swaps the omnibox textfield implementation.
+extern const base::Feature kIOSNewOmniboxImplementation;
+
 // Feature flag that enables persisting the Crash Restore Infobar across
 // navigations.
 extern const base::Feature kIOSPersistCrashRestore;