ui: Cleanup class/struct forward declarations

chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java
index 5f75e9039dcbd26b0a0300d16524615433debdee..e12690f63cc5cd1825b91ca2b3b7e380551f3544 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java
@@ -4,14 +4,21 @@
 
 package org.chromium.chrome.browser.webapps;
 
+import android.content.Context;
+import android.content.DialogInterface;
+import android.content.Intent;
 import android.os.StrictMode;
+import android.provider.Settings;
+import android.support.v7.app.AlertDialog;
 
 import org.chromium.base.CommandLine;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
 import org.chromium.base.annotations.CalledByNative;
+import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeFeatureList;
 import org.chromium.chrome.browser.ChromeSwitches;
+import org.chromium.chrome.browser.ChromeVersionInfo;
 import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
 import org.chromium.webapk.lib.client.WebApkValidator;
 
@@ -60,19 +67,97 @@ public class ChromeWebApkHost {
     }
 
     /**
+     * Show dialog warning user that "installation from unknown sources" is required by the WebAPK
+     * experiment if:
+     * - The user toggled the --enable-webapk command line flag via chrome://flags
+     * AND
+     * - WebAPKs are not disabled via variations kill switch.
+     * Must be run prior to {@link cacheEnabledStateForNextLaunch}.
+     */
+    public static void launchWebApkRequirementsDialogIfNeeded(Context context) {
+        // Show dialog on Canary & Dev. Installation via "unknown sources" is disabled via
+        // variations on other channels.
+        if (!ChromeVersionInfo.isCanaryBuild() && !ChromeVersionInfo.isDevBuild()) return;
+
+        Context applicationContext = ContextUtils.getApplicationContext();
+        boolean wasCommandLineFlagEnabled = ChromePreferenceManager.getInstance(applicationContext)
+                                                    .getCachedWebApkCommandLineEnabled();
+        if (computeEnabled() && !wasCommandLineFlagEnabled
+                && !installingFromUnknownSourcesAllowed(applicationContext)) {
+            showUnknownSourcesNeededDialog(context);
+        }
+    }
+
+    /**
      * Once native is loaded we can consult the command-line (set via about:flags) and also finch
      * state to see if we should enable WebAPKs.
      */
     public static void cacheEnabledStateForNextLaunch() {
-        boolean wasEnabled = isEnabledInPrefs();
-        CommandLine instance = CommandLine.getInstance();
-        boolean isEnabled = ChromeFeatureList.isEnabled(ChromeFeatureList.WEBAPKS)
-                && instance.hasSwitch(ChromeSwitches.ENABLE_WEBAPK);
+        ChromePreferenceManager preferenceManager =
+                ChromePreferenceManager.getInstance(ContextUtils.getApplicationContext());
+
+        boolean wasCommandLineEnabled = preferenceManager.getCachedWebApkCommandLineEnabled();
+        boolean isCommandLineEnabled = isCommandLineFlagSet();
+        if (isCommandLineEnabled != wasCommandLineEnabled) {
+            // {@link launchWebApkRequirementsDialogIfNeeded()} is skipped the first time Chrome is
+            // launched so do caching here instead.
+            preferenceManager.setCachedWebApkCommandLineEnabled(isCommandLineEnabled);
+        }
 
+        boolean wasEnabled = isEnabledInPrefs();
+        boolean isEnabled = computeEnabled();
         if (isEnabled != wasEnabled) {
             Log.d(TAG, "WebApk setting changed (%s => %s)", wasEnabled, isEnabled);
-            ChromePreferenceManager.getInstance(ContextUtils.getApplicationContext())
-                    .setCachedWebApkRuntimeEnabled(isEnabled);
+            preferenceManager.setCachedWebApkRuntimeEnabled(isEnabled);
+        }
+    }
+
+    /** Returns whether the --enable-webapk command line flag is set */
+    private static boolean isCommandLineFlagSet() {
+        return CommandLine.getInstance().hasSwitch(ChromeSwitches.ENABLE_WEBAPK);
+    }
+
+    /** Returns whether we should enable WebAPKs */
+    private static boolean computeEnabled() {
+        return isCommandLineFlagSet() && ChromeFeatureList.isEnabled(ChromeFeatureList.WEBAPKS);
+    }
+
+    /**
+     * Returns whether the user has enabled installing apps from sources other than the Google Play
+     * Store.
+     */
+    private static boolean installingFromUnknownSourcesAllowed(Context context) {
+        try {
+            return Settings.Secure.getInt(
+                           context.getContentResolver(), Settings.Secure.INSTALL_NON_MARKET_APPS)
+                    == 1;
+        } catch (Settings.SettingNotFoundException e) {
+            return false;
         }
     }
+
+    /**
+     * Show dialog warning user that "installation from unknown sources" is required by the WebAPK
+     * experiment.
+     */
+    private static void showUnknownSourcesNeededDialog(final Context context) {
+        AlertDialog.Builder builder = new AlertDialog.Builder(context);
+        builder.setTitle(R.string.webapk_unknown_sources_dialog_title);
+        builder.setMessage(R.string.webapk_unknown_sources_dialog_message);
+        builder.setPositiveButton(R.string.webapk_unknown_sources_settings_button,
+                new DialogInterface.OnClickListener() {
+                    @Override
+                    public void onClick(DialogInterface dialog, int id) {
+                        // Open Android Security settings.
+                        Intent intent = new Intent(Settings.ACTION_SECURITY_SETTINGS);
+                        context.startActivity(intent);
+                    }
+                });
+        builder.setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
+            @Override
+            public void onClick(DialogInterface dialog, int id) {}
+        });
+        AlertDialog dialog = builder.create();
+        dialog.show();
+    }
 }