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 ae712eea2625fe1a173ffb7242e3bb42f54acc50..40ca9d818a1b57e7968c87beba893abd86954808 100644
--- a/chrome/browser/android/webapk/chrome_webapk_host.cc
+++ b/chrome/browser/android/webapk/chrome_webapk_host.cc
@@ -13,6 +13,9 @@ namespace {
 // Variations flag to enable installing WebAPKs using Google Play.
 const char* kPlayInstall = "play_install";
 
+// Variations flag to enable launching WebAPK renderers.
+const char* kWebApkRenderer = "webapk_renderer";

[dominickn, 2017/02/23 00:17:28]

It's not clear what true and false mean here. Can this variable and constant be
something like, "launch_renderer_in_webapk_process" /
kLaunchRendererInWebApkProcess?

[F, 2017/02/23 01:15:43]

Done.

+
 }  // anonymous namespace
 
 // static
@@ -35,6 +38,14 @@ jboolean CanUseGooglePlayToInstallWebApk(
 }
 
 // static
+jboolean CanLaunchWebApkRenderer(

[dominickn, 2017/02/23 00:17:28]

CanLaunchRendererInWebApkProcess ?

[F, 2017/02/23 01:15:43]

Done.

+    JNIEnv* env,
+    const base::android::JavaParamRef<jclass>& clazz) {
+  return variations::GetVariationParamValueByFeature(
+             chrome::android::kImprovedA2HS, kWebApkRenderer) == "true";
+}
+
+// static
 jboolean CanInstallFromUnknownSources(
     JNIEnv* env,
     const base::android::JavaParamRef<jclass>& clazz) {