Add chrome://flags#enable-web-authentication-touch-id

This turns the existing WebAuthenticationTouchId feature into a
chrome://flags flag.

Bug: 678128
Change-Id: I8741f1d66409bdf636645c79cfb2145d679cb8d9
Reviewed-on: https://chromium-review.googlesource.com/1130699Reviewed-by: Kim Paulhamus <kpaulhamus@chromium.org>
Commit-Queue: Martin Kreichgauer <martinkr@google.com>
Cr-Commit-Position: refs/heads/master@{#574001}

chrome/browser/about_flags.cc

@@ -4046,6 +4046,13 @@ const FeatureEntry kFeatureEntries[] = {
      FEATURE_VALUE_TYPE(
          features::kAllowSignedHTTPExchangeCertsWithoutExtension)},
 
+#if defined(OS_MACOSX)
+    {"enable-web-authentication-touch-id",
+     flag_descriptions::kEnableWebAuthenticationTouchIdName,
+     flag_descriptions::kEnableWebAuthenticationTouchIdDescription, kOsMac,
+     FEATURE_VALUE_TYPE(device::kWebAuthTouchId)},
+#endif
+
     // NOTE: Adding a new flag requires adding a corresponding entry to enum
     // "LoginCustomFlags" in tools/metrics/histograms/enums.xml. See "Flag
     // Histograms" in tools/metrics/histograms/README.md (run the

chrome/browser/flag_descriptions.cc

@@ -2787,6 +2787,11 @@ const char kDialogTouchBarName[] = "Dialog Touch Bar";
 const char kDialogTouchBarDescription[] =
     "Shows Dialog buttons on the Touch Bar.";
 
+const char kEnableWebAuthenticationTouchIdName[] =
+    "Web Authentication API Touch ID support";
+const char kEnableWebAuthenticationTouchIdDescription[] =
+    "Enables a built-in Touch ID authenticator for the Web Authentication API.";
+
 const char kHostedAppsInWindowsName[] =
     "Allow hosted apps to be opened in windows";
 const char kHostedAppsInWindowsDescription[] =

chrome/browser/flag_descriptions.h

@@ -1690,6 +1690,9 @@ extern const char kContentFullscreenDescription[];
 extern const char kDialogTouchBarName[];
 extern const char kDialogTouchBarDescription[];
 
+extern const char kEnableWebAuthenticationTouchIdName[];
+extern const char kEnableWebAuthenticationTouchIdDescription[];
+
 extern const char kHostedAppsInWindowsName[];
 extern const char kHostedAppsInWindowsDescription[];
 

tools/metrics/histograms/enums.xml

@@ -27423,6 +27423,7 @@ from previous Chrome versions.
   <int value="-1943817505" label="SingleClickAutofill:enabled"/>
   <int value="-1943507605" label="enable-new-video-renderer"/>
   <int value="-1943313820" label="SystemKeyboardLock:disabled"/>
+  <int value="-1942730618" label="WebAuthenticationTouchId:disabled"/>
   <int value="-1941852572" label="floating-virtual-keyboard"/>
   <int value="-1940806558" label="enable-syncfs-directory-operation"/>
   <int value="-1940377152" label="MacRTL:enabled"/>
@@ -28845,6 +28846,7 @@ from previous Chrome versions.
   <int value="1070164693" label="MidiManagerDynamicInstantiation:disabled"/>
   <int value="1070300488" label="disable-webgl"/>
   <int value="1070449228" label="ContextualSuggestionsCarousel:enabled"/>
+  <int value="1071520357" label="WebAuthenticationTouchId:enabled"/>
   <int value="1072010558" label="NTPModernLayout:disabled"/>
   <int value="1074359194" label="UseSuggestionsEvenIfFew:enabled"/>
   <int value="1075637651" label="disable-tablet-splitview"/>