[WebApk] Enable WebApks by default.

Maintains the finch flag so that we can disable if the server encounters
issues but removes about:flag and defaults to enabled.
BUG=629181

Change-Id: I2fafaee9cf6227a0683983790ea2bb20d90197a8
Reviewed-on: https://chromium-review.googlesource.com/620532
Reviewed-by: Alexei Svitkine (very slow) <asvitkine@chromium.org>
Commit-Queue: Yaron Friedman <yfriedman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#495601}
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java
index 0bbd477..2381d68 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java
@@ -188,7 +188,6 @@
     // Whether we show an important sites dialog in the "Clear Browsing Data" flow.
     public static final String IMPORTANT_SITES_IN_CBD = "ImportantSitesInCBD";
     public static final String TABS_IN_CBD = "TabsInCBD";
-    public static final String IMPROVED_A2HS = "ImprovedA2HS";
     public static final String SEARCH_ENGINE_PROMO_EXISTING_DEVICE =
             "SearchEnginePromo.ExistingDevice";
     public static final String SEARCH_ENGINE_PROMO_NEW_DEVICE = "SearchEnginePromo.NewDevice";
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 9ac9a11..f8ac7e9 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -2738,9 +2738,6 @@
      ENABLE_DISABLE_VALUE_TYPE(switches::kEnableBrowserTaskScheduler,
                                switches::kDisableBrowserTaskScheduler)},
 #if defined(OS_ANDROID)
-    {"enable-improved-a2hs", flag_descriptions::kEnableWebapk,
-     flag_descriptions::kEnableWebapkDescription, kOsAndroid,
-     FEATURE_VALUE_TYPE(chrome::android::kImprovedA2HS)},
     {"no-credit-card-abort", flag_descriptions::kNoCreditCardAbort,
      flag_descriptions::kNoCreditCardAbortDescription, kOsAndroid,
      FEATURE_VALUE_TYPE(chrome::android::kNoCreditCardAbort)},
diff --git a/chrome/browser/android/chrome_feature_list.cc b/chrome/browser/android/chrome_feature_list.cc
index 69ea7ad..e1cca56 100644
--- a/chrome/browser/android/chrome_feature_list.cc
+++ b/chrome/browser/android/chrome_feature_list.cc
@@ -208,8 +208,10 @@
 
 // Makes "Add to Home screen" in the app menu generate an APK for the shortcut
 // URL which opens Chrome in fullscreen.
+// This feature is kept around so that we have a kill-switch in case of server
+// issues.
 const base::Feature kImprovedA2HS{"ImprovedA2HS",
-                                  base::FEATURE_DISABLED_BY_DEFAULT};
+                                  base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kSearchEnginePromoExistingDevice{
     "SearchEnginePromo.ExistingDevice", base::FEATURE_ENABLED_BY_DEFAULT};
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index 03023a40..3396900 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -1682,13 +1682,6 @@
     "Enable custom logic for special locales. In this mode, Chrome might "
     "behave differently in some locales.";
 
-const char kEnableWebapk[] = "Enable improved add to Home screen";
-const char kEnableWebapkDescription[] =
-    R"*(Packages "Progressive Web Apps" so that they can integrate more )*"
-    R"*(deeply with Android. A Chrome server is used to package sites. In )*"
-    R"*(Chrome Canary and Chrome Dev, this requires “Untrusted )*"
-    R"*(sources” to be enabled in Android security settings.)*";
-
 const char kEnableWebNfcName[] = "WebNFC";
 const char kEnableWebNfcDescription[] = "Enable WebNFC support.";
 
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 55a5f0b..38ec5553 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -1022,9 +1022,6 @@
 extern const char kEnableSpecialLocaleName[];
 extern const char kEnableSpecialLocaleDescription[];
 
-extern const char kEnableWebapk[];
-extern const char kEnableWebapkDescription[];
-
 extern const char kEnableWebNfcName[];
 extern const char kEnableWebNfcDescription[];
 
diff --git a/testing/variations/fieldtrial_testing_config.json b/testing/variations/fieldtrial_testing_config.json
index 41e4ca0..4c1443a 100644
--- a/testing/variations/fieldtrial_testing_config.json
+++ b/testing/variations/fieldtrial_testing_config.json
@@ -3342,24 +3342,6 @@
             ]
         }
     ],
-    "WebApkGooglePlay": [
-        {
-            "platforms": [
-                "android"
-            ],
-            "experiments": [
-                {
-                    "name": "Enabled",
-                    "params": {
-                        "play_install": "true"
-                    },
-                    "enable_features": [
-                        "ImprovedA2HS"
-                    ]
-                }
-            ]
-        }
-    ],
     "WebBluetoothBlocklist": [
         {
             "platforms": [