Bug 1270191 - Move Experiments to env var solution. r=grisha

MozReview-Commit-ID: 5Rpdyg7zpNG

--HG--
extra : rebase_source : 1642484993287d489060e95e3fbeb62232b422c6

mobile/android/base/java/org/mozilla/gecko/BrowserApp.java

@@ -96,6 +96,7 @@ import org.mozilla.gecko.util.FloatUtils;
 import org.mozilla.gecko.util.GamepadUtils;
 import org.mozilla.gecko.util.GeckoEventListener;
 import org.mozilla.gecko.util.HardwareUtils;
+import org.mozilla.gecko.util.IntentUtils;
 import org.mozilla.gecko.util.MenuUtils;
 import org.mozilla.gecko.util.NativeEventListener;
 import org.mozilla.gecko.util.NativeJSObject;
@@ -176,6 +177,7 @@ import java.net.URLEncoder;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.EnumSet;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
@@ -545,6 +547,7 @@ public class BrowserApp extends GeckoApp
         }
 
         final Intent intent = getIntent();
+        configureForTestsBasedOnEnvironment(intent);
 
         // This has to be prepared prior to calling GeckoApp.onCreate, because
         // widget code and BrowserToolbar need it, and they're created by the
@@ -760,12 +763,27 @@ public class BrowserApp extends GeckoApp
         }
     }
 
+    /**
+     * Sets up the testing configuration if the environment is configured as such.
+     *
+     * We need to read environment variables from the intent string
+     * extra because environment variables from our test harness aren't set
+     * until Gecko is loaded, and we need to know this before then.
+     *
+     * This method should be called early since other initialization
+     * may depend on its results.
+     */
+    private void configureForTestsBasedOnEnvironment(final Intent intent) {
+        final HashMap<String, String> envVars = IntentUtils.getEnvVarMap(intent);
+        Experiments.setDisabledFromEnvVar(envVars);
+    }
+
     /**
      * Initializes the default Switchboard URLs the first time.
      * @param intent
      */
-    private void initSwitchboard(Intent intent) {
-        if (Experiments.isDisabled(new SafeIntent(intent)) || !AppConstants.MOZ_SWITCHBOARD) {
+    private void initSwitchboard(final Intent intent) {
+        if (Experiments.isDisabled() || !AppConstants.MOZ_SWITCHBOARD) {
             return;
         }
 

mobile/android/base/java/org/mozilla/gecko/util/Experiments.java

@@ -6,8 +6,8 @@ package org.mozilla.gecko.util;
 
 import android.content.Context;
 
+import android.support.annotation.NonNull;
 import android.util.Log;
-import org.mozilla.gecko.mozglue.SafeIntentUtils.SafeIntent;
 import android.text.TextUtils;
 
 import com.keepsafe.switchboard.Preferences;
@@ -16,6 +16,7 @@ import org.mozilla.gecko.GeckoSharedPrefs;
 
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Map;
 
 /**
  * This class should reflect the experiment names found in the Switchboard experiments config here:
@@ -24,6 +25,8 @@ import java.util.List;
 public class Experiments {
     private static final String LOGTAG = "GeckoExperiments";
 
+    private static final String ENVVAR_DISABLED = "MOZ_DISABLE_SWITCHBOARD";
+
     // Show a system notification linking to a "What's New" page on app update.
     public static final String WHATSNEW_NOTIFICATION = "whatsnew-notification";
 
@@ -58,31 +61,22 @@ public class Experiments {
     private static volatile Boolean disabled = null;
 
     /**
-     * Determines whether Switchboard is disabled by the MOZ_DISABLE_SWITCHBOARD
-     * environment variable. We need to read this value from the intent string
-     * extra because environment variables from our test harness aren't set
-     * until Gecko is loaded, and we need to know this before then.
-     *
-     * @param intent Main intent that launched the app
-     * @return Whether Switchboard is disabled
+     * As a sanity check, this method may only be called once.
      */
-    public static boolean isDisabled(SafeIntent intent) {
+    public static void setDisabledFromEnvVar(@NonNull final Map<String, String> envVarMap) {
         if (disabled != null) {
-            return disabled;
+            throw new IllegalStateException("Disabled state already set");
         }
+        disabled = envVarMap.containsKey(ENVVAR_DISABLED);
+        if (disabled) {
+            Log.d(LOGTAG, "Switchboard disabled by environment variable: " + ENVVAR_DISABLED);
+        }
+    }
 
-        String env = intent.getStringExtra("env0");
-        for (int i = 1; env != null; i++) {
-            if (env.startsWith("MOZ_DISABLE_SWITCHBOARD=")) {
-                if (!env.endsWith("=")) {
-                    Log.d(LOGTAG, "Switchboard disabled by MOZ_DISABLE_SWITCHBOARD environment variable");
-                    disabled = true;
-                    return disabled;
-                }
-            }
-            env = intent.getStringExtra("env" + i);
+    public static boolean isDisabled() {
+        if (disabled == null) {
+            throw new IllegalStateException("Disabled state not yet set.");
         }
-        disabled = false;
         return disabled;
     }