Move existing @IntDef elements inside existing ParallelRequestStatus

@IntDef/@StringDef annotation are preferred way for declaring
set of String/int values.

1. they need less space in APK than enum, see
https://developer.android.com/topic/performance/reduce-apk-size#remove-enums
2. they give more control over allowed values than "static final" values

Main goal of patch is writing "static final" values, enum
and some classes in one common @IntDef/@StringDef form:

1. with @IntDef/@StringDef first, @Retention second
   and related @interface third
2. with values inside @interface
3. with NUM_ENTRIES declaring number of entries if necessary
4. with comment about numbering from 0 without gaps when necessary
5. with @Retention(RetentionPolicy.SOURCE)
6. without "static final" in the @interface

Change-Id: I2d2f80b5d0b84b1315016903b74f06d10ab6d4e8
Reviewed-on: https://chromium-review.googlesource.com/1146189Reviewed-by: Egor Pasko (futex_wait(&amp;secret))) <pasko@chromium.org>
Commit-Queue: Marcin Wiącek <marcin@mwiacek.com>
Cr-Commit-Position: refs/heads/master@{#577628}

chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabsConnection.java

@@ -75,6 +75,8 @@ import org.chromium.content_public.common.Referrer;
 import java.io.BufferedReader;
 import java.io.FileReader;
 import java.io.IOException;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashSet;
@@ -147,27 +149,31 @@ public class CustomTabsConnection {
     static final String PARALLEL_REQUEST_URL_KEY =
             "android.support.customtabs.PARALLEL_REQUEST_URL";
 
-    @IntDef({PARALLEL_REQUEST_NO_REQUEST, PARALLEL_REQUEST_SUCCESS,
-            PARALLEL_REQUEST_FAILURE_NOT_INITIALIZED, PARALLEL_REQUEST_FAILURE_NOT_AUTHORIZED,
-            PARALLEL_REQUEST_FAILURE_INVALID_URL, PARALLEL_REQUEST_FAILURE_INVALID_REFERRER,
-            PARALLEL_REQUEST_FAILURE_INVALID_REFERRER_FOR_SESSION})
-    @interface ParallelRequestStatus {}
-
-    @VisibleForTesting
-    static final int PARALLEL_REQUEST_NO_REQUEST = 0;
-    @VisibleForTesting
-    static final int PARALLEL_REQUEST_SUCCESS = 1;
-    @VisibleForTesting
-    static final int PARALLEL_REQUEST_FAILURE_NOT_INITIALIZED = 2;
-    @VisibleForTesting
-    static final int PARALLEL_REQUEST_FAILURE_NOT_AUTHORIZED = 3;
-    @VisibleForTesting
-    static final int PARALLEL_REQUEST_FAILURE_INVALID_URL = 4;
-    @VisibleForTesting
-    static final int PARALLEL_REQUEST_FAILURE_INVALID_REFERRER = 5;
-    @VisibleForTesting
-    static final int PARALLEL_REQUEST_FAILURE_INVALID_REFERRER_FOR_SESSION = 6;
-    private static final int PARALLEL_REQUEST_STATUS_MAX = 7;
+    @IntDef({ParallelRequestStatus.NO_REQUEST, ParallelRequestStatus.SUCCESS,
+            ParallelRequestStatus.FAILURE_NOT_INITIALIZED,
+            ParallelRequestStatus.FAILURE_NOT_AUTHORIZED, ParallelRequestStatus.FAILURE_INVALID_URL,
+            ParallelRequestStatus.FAILURE_INVALID_REFERRER,
+            ParallelRequestStatus.FAILURE_INVALID_REFERRER_FOR_SESSION})
+    @Retention(RetentionPolicy.SOURCE)
+    @interface ParallelRequestStatus {
+        // Values should start from 0 and can't have gaps (they're used for indexing
+        // PARALLEL_REQUEST_MESSAGES).
+        @VisibleForTesting
+        int NO_REQUEST = 0;
+        @VisibleForTesting
+        int SUCCESS = 1;
+        @VisibleForTesting
+        int FAILURE_NOT_INITIALIZED = 2;
+        @VisibleForTesting
+        int FAILURE_NOT_AUTHORIZED = 3;
+        @VisibleForTesting
+        int FAILURE_INVALID_URL = 4;
+        @VisibleForTesting
+        int FAILURE_INVALID_REFERRER = 5;
+        @VisibleForTesting
+        int FAILURE_INVALID_REFERRER_FOR_SESSION = 6;
+        int NUM_ENTRIES = 7;
+    }
 
     private static final String[] PARALLEL_REQUEST_MESSAGES = {"No request", "Success",
             "Chrome not initialized", "Not authorized", "Invalid URL", "Invalid referrer",
@@ -175,7 +181,7 @@ public class CustomTabsConnection {
 
     private static final EnumeratedHistogramSample sParallelRequestStatusOnStart =
             new EnumeratedHistogramSample(
-                    "CustomTabs.ParallelRequestStatusOnStart", PARALLEL_REQUEST_STATUS_MAX);
+                    "CustomTabs.ParallelRequestStatusOnStart", ParallelRequestStatus.NUM_ENTRIES);
 
     private static final CustomTabsConnection sInstance =
             AppHooks.get().createCustomTabsConnection();
@@ -883,25 +889,26 @@ public class CustomTabsConnection {
     private int maybeStartParallelRequest(CustomTabsSessionToken session, Intent intent) {
         ThreadUtils.assertOnUiThread();
 
-        if (!intent.hasExtra(PARALLEL_REQUEST_URL_KEY)) return PARALLEL_REQUEST_NO_REQUEST;
+        if (!intent.hasExtra(PARALLEL_REQUEST_URL_KEY)) return ParallelRequestStatus.NO_REQUEST;
         if (!ChromeBrowserInitializer.getInstance(ContextUtils.getApplicationContext())
                         .hasNativeInitializationCompleted()) {
-            return PARALLEL_REQUEST_FAILURE_NOT_INITIALIZED;
+            return ParallelRequestStatus.FAILURE_NOT_INITIALIZED;
         }
         if (!mClientManager.getAllowParallelRequestForSession(session)) {
-            return PARALLEL_REQUEST_FAILURE_NOT_AUTHORIZED;
+            return ParallelRequestStatus.FAILURE_NOT_AUTHORIZED;
         }
         Uri referrer = intent.getParcelableExtra(PARALLEL_REQUEST_REFERRER_KEY);
         Uri url = intent.getParcelableExtra(PARALLEL_REQUEST_URL_KEY);
         int policy =
                 intent.getIntExtra(PARALLEL_REQUEST_REFERRER_POLICY_KEY, WebReferrerPolicy.DEFAULT);
-        if (url == null) return PARALLEL_REQUEST_FAILURE_INVALID_URL;
-        if (referrer == null) return PARALLEL_REQUEST_FAILURE_INVALID_REFERRER;
+        if (url == null) return ParallelRequestStatus.FAILURE_INVALID_URL;
+        if (referrer == null) return ParallelRequestStatus.FAILURE_INVALID_REFERRER;
         if (policy < 0 || policy > WebReferrerPolicy.LAST) policy = WebReferrerPolicy.DEFAULT;
 
-        if (url.toString().equals("") || !isValid(url)) return PARALLEL_REQUEST_FAILURE_INVALID_URL;
+        if (url.toString().equals("") || !isValid(url))
+            return ParallelRequestStatus.FAILURE_INVALID_URL;
         if (!canDoParallelRequest(session, referrer)) {
-            return PARALLEL_REQUEST_FAILURE_INVALID_REFERRER_FOR_SESSION;
+            return ParallelRequestStatus.FAILURE_INVALID_REFERRER_FOR_SESSION;
         }
 
         String urlString = url.toString();
@@ -911,7 +918,7 @@ public class CustomTabsConnection {
         if (mLogRequests) {
             Log.w(TAG, "startParallelRequest(%s, %s, %d)", urlString, referrerString, policy);
         }
-        return PARALLEL_REQUEST_SUCCESS;
+        return ParallelRequestStatus.SUCCESS;
     }
 
     /** @return Whether {@code session} can create a parallel request for a given

chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/DetachedResourceRequestTest.java

@@ -99,13 +99,13 @@ public class DetachedResourceRequestTest {
         CustomTabsSessionToken session = prepareSession();
 
         ThreadUtils.runOnUiThreadBlocking(() -> {
-            int expected = CustomTabsConnection.PARALLEL_REQUEST_NO_REQUEST;
+            int expected = CustomTabsConnection.ParallelRequestStatus.NO_REQUEST;
             HistogramDelta histogram =
                     new HistogramDelta("CustomTabs.ParallelRequestStatusOnStart", expected);
             Assert.assertEquals(expected, mConnection.handleParallelRequest(session, new Intent()));
             Assert.assertEquals(1, histogram.getDelta());
 
-            expected = CustomTabsConnection.PARALLEL_REQUEST_FAILURE_INVALID_URL;
+            expected = CustomTabsConnection.ParallelRequestStatus.FAILURE_INVALID_URL;
             histogram = new HistogramDelta("CustomTabs.ParallelRequestStatusOnStart", expected);
             Intent intent =
                     prepareIntent(Uri.parse("android-app://this.is.an.android.app"), ORIGIN);
@@ -113,20 +113,21 @@ public class DetachedResourceRequestTest {
                     mConnection.handleParallelRequest(session, intent));
             Assert.assertEquals(1, histogram.getDelta());
 
-            expected = CustomTabsConnection.PARALLEL_REQUEST_FAILURE_INVALID_URL;
+            expected = CustomTabsConnection.ParallelRequestStatus.FAILURE_INVALID_URL;
             histogram = new HistogramDelta("CustomTabs.ParallelRequestStatusOnStart", expected);
             intent = prepareIntent(Uri.parse(""), ORIGIN);
             Assert.assertEquals("Should not allow an empty URL", expected,
                     mConnection.handleParallelRequest(session, intent));
             Assert.assertEquals(1, histogram.getDelta());
 
-            expected = CustomTabsConnection.PARALLEL_REQUEST_FAILURE_INVALID_REFERRER_FOR_SESSION;
+            expected =
+                    CustomTabsConnection.ParallelRequestStatus.FAILURE_INVALID_REFERRER_FOR_SESSION;
             histogram = new HistogramDelta("CustomTabs.ParallelRequestStatusOnStart", expected);
             intent = prepareIntent(Uri.parse("HTTPS://foo.bar"), Uri.parse("wrong://origin"));
             Assert.assertEquals("Should not allow an arbitrary origin", expected,
                     mConnection.handleParallelRequest(session, intent));
 
-            expected = CustomTabsConnection.PARALLEL_REQUEST_SUCCESS;
+            expected = CustomTabsConnection.ParallelRequestStatus.SUCCESS;
             histogram = new HistogramDelta("CustomTabs.ParallelRequestStatusOnStart", expected);
             intent = prepareIntent(Uri.parse("HTTPS://foo.bar"), ORIGIN);
             Assert.assertEquals(expected, mConnection.handleParallelRequest(session, intent));
@@ -149,7 +150,7 @@ public class DetachedResourceRequestTest {
 
         Uri url = Uri.parse(mServer.getURL("/echotitle"));
         ThreadUtils.runOnUiThread(() -> {
-            Assert.assertEquals(CustomTabsConnection.PARALLEL_REQUEST_SUCCESS,
+            Assert.assertEquals(CustomTabsConnection.ParallelRequestStatus.SUCCESS,
                     mConnection.handleParallelRequest(session, prepareIntent(url, ORIGIN)));
         });
         cb.waitForCallback(0, 1);
@@ -163,7 +164,7 @@ public class DetachedResourceRequestTest {
         mServer = EmbeddedTestServer.createAndStartServer(mContext);
         final Uri url = Uri.parse(mServer.getURL("/set-cookie?acookie"));
         ThreadUtils.runOnUiThreadBlocking(() -> {
-            Assert.assertEquals(CustomTabsConnection.PARALLEL_REQUEST_SUCCESS,
+            Assert.assertEquals(CustomTabsConnection.ParallelRequestStatus.SUCCESS,
                     mConnection.handleParallelRequest(session, prepareIntent(url, ORIGIN)));
         });
 
@@ -256,7 +257,7 @@ public class DetachedResourceRequestTest {
         });
         final Uri url = Uri.parse(mServer.getURL("/set-cookie?acookie"));
         ThreadUtils.runOnUiThreadBlocking(() -> {
-            Assert.assertEquals(CustomTabsConnection.PARALLEL_REQUEST_SUCCESS,
+            Assert.assertEquals(CustomTabsConnection.ParallelRequestStatus.SUCCESS,
                     mConnection.handleParallelRequest(session, prepareIntent(url, ORIGIN)));
         });
 
@@ -286,7 +287,7 @@ public class DetachedResourceRequestTest {
         CustomTabsSessionToken session = prepareSession(url);
 
         ThreadUtils.runOnUiThreadBlocking(() -> {
-            Assert.assertEquals(CustomTabsConnection.PARALLEL_REQUEST_SUCCESS,
+            Assert.assertEquals(CustomTabsConnection.ParallelRequestStatus.SUCCESS,
                     mConnection.handleParallelRequest(session, prepareIntent(url, origin)));
         });
 
@@ -343,7 +344,7 @@ public class DetachedResourceRequestTest {
         Uri url = Uri.parse(mServer.getURL(relativeUrl));
 
         ThreadUtils.runOnUiThreadBlocking(() -> {
-            Assert.assertEquals(CustomTabsConnection.PARALLEL_REQUEST_SUCCESS,
+            Assert.assertEquals(CustomTabsConnection.ParallelRequestStatus.SUCCESS,
                     mConnection.handleParallelRequest(session, prepareIntent(url, ORIGIN)));
         });
         readFromSocketCallback.waitForCallback(0);