Chrome talks to Play to install WebAPKs.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 581fdf2e28fd6d90c20d3d32884843e365e90f62..d0e98c83579226fe840c5ad00300f53dfd6af4f7 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -1036,6 +1036,10 @@ const char kEnableHostedMode[] = "enable-hosted-mode";
 // unresponsive web content.
 const char kEnableHungRendererInfoBar[] = "enable-hung-renderer-infobar";
 
+// Enables Play Store to install WebAPKs generated by "Add to Home screen" in
+// the app menu.
+const char kEnablePlayInstallWebApk[] = "enable-play-install-improved-a2hs";
+
 // Enables "Add to Home screen" in the app menu to generate WebAPKs.
 const char kEnableWebApk[] = "enable-improved-a2hs";