Add a variations parameter to control WebAPK renderer launching.

chrome/browser/android/webapk/chrome_webapk_host.cc

Index: chrome/browser/android/webapk/chrome_webapk_host.cc
diff --git a/chrome/browser/android/webapk/chrome_webapk_host.cc b/chrome/browser/android/webapk/chrome_webapk_host.cc
index 0d734904f9eefff4d2135903d380d4b30143925e..f7653c4e65b8d1340b3cacdde5b8721718ce5eb2 100644
--- a/chrome/browser/android/webapk/chrome_webapk_host.cc
+++ b/chrome/browser/android/webapk/chrome_webapk_host.cc
@@ -13,6 +13,10 @@ namespace {
 // Variations flag to enable installing WebAPKs using Google Play.
 const char* kPlayInstall = "play_install";
 
+// Variations flag to enable launching Chrome renderer in WebAPK process.
+const char* kLaunchRendererInWebApkProcess =
+    "launch_renderer_in_webapk_process";
+
 }  // anonymous namespace
 
 // static
@@ -42,6 +46,15 @@ jboolean CanUseGooglePlayToInstallWebApk(
 }
 
 // static
+jboolean CanLaunchRendererInWebApkProcess(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jclass>& clazz) {
+  return variations::GetVariationParamValueByFeature(
+             chrome::android::kImprovedA2HS, kLaunchRendererInWebApkProcess) ==
+         "true";
+}
+
+// static
 jboolean CanInstallFromUnknownSources(
     JNIEnv* env,
     const base::android::JavaParamRef<jclass>& clazz) {