Fall back to shortcut A2HS when Phonesky is out of date or unavailable.

chrome/browser/android/webapk/chrome_webapk_host.h

Index: chrome/browser/android/webapk/chrome_webapk_host.h
diff --git a/chrome/browser/android/webapk/chrome_webapk_host.h b/chrome/browser/android/webapk/chrome_webapk_host.h
index dc84ea17f89f5962f4a7660446398e731274a249..65b77a43554e948925cbec884671eb059b5d9b02 100644
--- a/chrome/browser/android/webapk/chrome_webapk_host.h
+++ b/chrome/browser/android/webapk/chrome_webapk_host.h
@@ -7,20 +7,51 @@
 
 #include <jni.h>
 
+#include "base/android/scoped_java_ref.h"
+#include "base/callback.h"
 #include "base/macros.h"
 
+
 // ChromeWebApkHost is the C++ counterpart of org.chromium.chrome.browser's
 // ChromeWebApkHost in Java.
 class ChromeWebApkHost {
  public:
+  using CanUseGooglePlayInstallApiCallback = base::Callback<void(bool)>;
+
+  ChromeWebApkHost();
+
   // Registers JNI hooks.
   static bool Register(JNIEnv* env);
 
   // Returns whether the "enalbe-webapk" is turned on.
   static bool AreWebApkEnabled();
 
+  // Returns whether the Google Play Install is allowed.
+  static bool CanUseGooglePlayToInstallWebApk();
+
+  // Checks whether Google Play Install API is available.

[pkotwicz, 2017/02/03 18:56:32]

Nit: Document that the callback can be called synchronously

[Xi Han, 2017/02/03 22:16:21]

Done.

+  void CanUseGooglePlayInstallApi(
+      const CanUseGooglePlayInstallApiCallback& Callback);
+
+  // Called when the check of whether the Google Play Install API is available
+  // is done.
+  void OnCanUseGooglePlayInstallApi(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      jboolean is_available);
+
  private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ChromeWebApkHost);
+  ~ChromeWebApkHost();
+
+  // Create the Java object.
+  void CreateJavaRef();
+
+  // Points to the Java Object.
+  base::android::ScopedJavaGlobalRef<jobject> java_ref_;
+
+  CanUseGooglePlayInstallApiCallback callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeWebApkHost);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_WEBAPK_CHROME_WEBAPK_HOST_H_