Adds flag for using custom tab UI.

This flag will control whether or not the new custom tab bar UI is used.

Bug: 853593
Change-Id: Ie8ab91d10fc6543ab560a50795dd5e26b8e31146
Reviewed-on: https://chromium-review.googlesource.com/c/1312135
Commit-Queue: Jay Harris <harrisjay@chromium.org>
Reviewed-by: Matt Giuca <mgiuca@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604787}

chrome/browser/about_flags.cc

@@ -2298,6 +2298,10 @@ const FeatureEntry kFeatureEntries[] = {
     {"enable-system-webapps", flag_descriptions::kEnableSystemWebAppsName,
      flag_descriptions::kEnableSystemWebAppsDescription, kOsDesktop,
      FEATURE_VALUE_TYPE(features::kSystemWebApps)},
+    {"enable-desktop-pwas-custom-tab-ui",
+     flag_descriptions::kDesktopPWAsCustomTabUIName,
+     flag_descriptions::kDesktopPWAsCustomTabUIDescription, kOsDesktop,
+     FEATURE_VALUE_TYPE(features::kDesktopPWAsCustomTabUI)},
     {"enable-desktop-pwas-stay-in-window",
      flag_descriptions::kDesktopPWAsStayInWindowName,
      flag_descriptions::kDesktopPWAsStayInWindowDescription, kOsDesktop,

chrome/browser/flag_descriptions.cc

@@ -531,11 +531,16 @@ const char kEnableDesktopPWAsLinkCapturingDescription[] =
     "URLs that are in-scope of Desktop PWAs will open in a window. Requires "
     "#enable-desktop-pwas.";
 
+const char kDesktopPWAsCustomTabUIName[] = "Desktop PWAs Custom Tab UI";
+const char kDesktopPWAsCustomTabUIDescription[] =
+    "Browsing out-of-scope links in a desktop PWA will use the custom tab UI "
+    "for displaying the page title and origin instead of the location bar.";
+
 const char kDesktopPWAsStayInWindowName[] =
     "Desktop PWAs out-of-scope links open in the app window";
 const char kDesktopPWAsStayInWindowDescription[] =
-    "Links to sites in a different scope will open in a custom "
-    "tab (inside the PWA window) as opposed to in the browser.";
+    "Links to sites in a different scope will open inside the PWA window as "
+    "opposed to in the browser.";
 
 const char kEnableSystemWebAppsName[] = "System Web Apps";
 const char kEnableSystemWebAppsDescription[] =

chrome/browser/flag_descriptions.h

@@ -349,6 +349,9 @@ extern const char kEnableDesktopPWAsDescription[];
 extern const char kEnableDesktopPWAsLinkCapturingName[];
 extern const char kEnableDesktopPWAsLinkCapturingDescription[];
 
+extern const char kDesktopPWAsCustomTabUIName[];
+extern const char kDesktopPWAsCustomTabUIDescription[];
+
 extern const char kDesktopPWAsStayInWindowName[];
 extern const char kDesktopPWAsStayInWindowDescription[];
 

chrome/common/chrome_features.cc

@@ -204,6 +204,11 @@ const base::Feature kDesktopPWAWindowing {
 const base::Feature kDesktopPWAsLinkCapturing{
     "DesktopPWAsLinkCapturing", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Determines whether out of scope pages in the hosted app will use the
+// custom tab UI.
+const base::Feature kDesktopPWAsCustomTabUI{"DesktopPWAsCustomTabUI",
+                                            base::FEATURE_ENABLED_BY_DEFAULT};
+
 // Determines whether in scope requests are always opened in the same window.
 const base::Feature kDesktopPWAsStayInWindow{"DesktopPWAsStayInWindow",
                                              base::FEATURE_ENABLED_BY_DEFAULT};

chrome/common/chrome_features.h

@@ -128,6 +128,9 @@ extern const base::Feature kDesktopPWAWindowing;
 COMPONENT_EXPORT(CHROME_FEATURES)
 extern const base::Feature kDesktopPWAsLinkCapturing;
 
+COMPONENT_EXPORT(CHROME_FEATURES)
+extern const base::Feature kDesktopPWAsCustomTabUI;
+
 COMPONENT_EXPORT(CHROME_FEATURES)
 extern const base::Feature kDesktopPWAsStayInWindow;
 

tools/metrics/histograms/enums.xml

@@ -29447,6 +29447,7 @@ from previous Chrome versions.
   <int value="-1174267639" label="ClientLoFi:disabled"/>
   <int value="-1172572865" label="NTPShowGoogleGInOmnibox:enabled"/>
   <int value="-1172204005" label="enable-offline-auto-reload-visible-only"/>
+  <int value="-1167992523" label="DesktopPWAsCustomTabUI:disabled"/>
   <int value="-1166715563" label="ChromeOSAssistant:disabled"/>
   <int value="-1162944097" label="enable-color-correct-rendering"/>
   <int value="-1161409696" label="MediaRemotingEncrypted:enabled"/>
@@ -30070,6 +30071,7 @@ from previous Chrome versions.
   <int value="37045987" label="AutofillPreviewStyleExperiment:disabled"/>
   <int value="42098736" label="TranslateAndroidManualTrigger:disabled"/>
   <int value="42844603" label="AndroidSurfaceControl:disabled"/>
+  <int value="43951968" label="DesktopPWAsCustomTabUI:enabled"/>
   <int value="44088203" label="ExpensiveBackgroundTimerThrottling:enabled"/>
   <int value="48159177" label="reduced-referrer-granularity"/>
   <int value="48223610" label="SiteSettings:disabled"/>