Bug 1554256 - Read GeckoView configuration file in release builds whe…

…n package is the current Android "debug-app". r=geckoview-reviewers,snorp

Bug 1533385 taught GeckoView to read configuration from a file. But
right now, release APKs don't read that configuration: see the
documentation at See
https://mozilla.github.io/geckoview/tutorials/automation.html#enabling-reading-configuration-from-a-file-for-release-builds.
However, Android has a flag -- the "debug_app" flag -- that Chrome
uses to control this configuration file behaviour, and this commit
makes GeckoView uses that flag as well.

To use this, invoke `adb shell am set-debug-app --persistent PACKAGE`
(see https://developer.android.com/studio/command-line/adb).

Differential Revision: https://phabricator.services.mozilla.com/D32511

--HG--
extra : moz-landing-system : lando

mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/ContextUtils.java

@@ -7,8 +7,12 @@
 package org.mozilla.gecko.util;
 
 import android.content.Context;
+import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
+import android.os.Build;
+import android.provider.Settings;
+import android.support.annotation.NonNull;
 import android.text.TextUtils;
 
 public class ContextUtils {
@@ -46,4 +50,23 @@ public static boolean isInstalledFromGooglePlay(final Context context) {
 
         return INSTALLER_GOOGLE_PLAY.equals(installerPackageName);
     }
+
+    public static boolean isApplicationDebuggable(final @NonNull Context context) {
+        final ApplicationInfo applicationInfo = context.getApplicationInfo();
+        return (applicationInfo.flags & ApplicationInfo.FLAG_DEBUGGABLE) != 0;
+    }
+
+    public static boolean isApplicationCurrentDebugApp(final @NonNull Context context) {
+        final ApplicationInfo applicationInfo = context.getApplicationInfo();
+
+        final String currentDebugApp;
+        if (Build.VERSION.SDK_INT >= 17) {
+            currentDebugApp = Settings.Global.getString(context.getContentResolver(),
+                    Settings.Global.DEBUG_APP);
+        } else {
+            currentDebugApp = Settings.System.getString(context.getContentResolver(),
+                    Settings.System.DEBUG_APP);
+        }
+        return applicationInfo.packageName.equals(currentDebugApp);
+    }
 }

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoRuntime.java

@@ -15,7 +15,6 @@
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
-import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.ServiceInfo;
 import android.content.res.Configuration;
@@ -37,6 +36,7 @@
 import org.mozilla.gecko.GeckoThread;
 import org.mozilla.gecko.PrefsHelper;
 import org.mozilla.gecko.util.BundleEventListener;
+import org.mozilla.gecko.util.ContextUtils;
 import org.mozilla.gecko.util.DebugConfig;
 import org.mozilla.gecko.util.EventCallback;
 import org.mozilla.gecko.util.GeckoBundle;
@@ -264,11 +264,10 @@ private static String getProcessName(final Context context) {
         String configFilePath = settings.getConfigFilePath();
         if (configFilePath == null) {
             // Default to /data/local/tmp/$PACKAGE-geckoview-config.yaml if android:debuggable="true"
-            // and to not read configuration from a file if android:debuggable="false".
-            final ApplicationInfo applicationInfo = context.getApplicationInfo();
-            final boolean isPackageDebuggable = (applicationInfo.flags & ApplicationInfo.FLAG_DEBUGGABLE) != 0;
-            if (isPackageDebuggable) {
-                configFilePath = String.format(CONFIG_FILE_PATH_TEMPLATE, applicationInfo.packageName);
+            // or if this application is the current Android "debug_app", and to not read configuration
+            // from a file otherwise.
+            if (ContextUtils.isApplicationDebuggable(context) || ContextUtils.isApplicationCurrentDebugApp(context)) {
+                configFilePath = String.format(CONFIG_FILE_PATH_TEMPLATE, context.getApplicationInfo().packageName);
             }
         }