Revert "Sync: Delete ModelTypeHelper.java"

This reverts commit aae3a263.

Reason for revert: breaks fuchsia_x64 on cq, crbug.com/1099786

Original change's description:
> Sync: Delete ModelTypeHelper.java
> 
> It was part of the old invalidations implementation, and not used
> anymore.
> This was the last reference from sync to third_party/cacheinvalidation,
> so all references to that are also removed from BUILD.gn and DEPS
> files.
> 
> Bug: 1099672
> Change-Id: I3491fa1cea04d0deebe68988cd3af5a5a4da1afb
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2270182
> Commit-Queue: Mikel Astiz <mastiz@chromium.org>
> Auto-Submit: Marc Treib <treib@chromium.org>
> Reviewed-by: Mikel Astiz <mastiz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#783025}

TBR=treib@chromium.org,mastiz@chromium.org

Change-Id: I463dd6d98c8b2c93734628557c01c376b231b62f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1099672
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2269746Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#783043}

components/sync/BUILD.gn

@@ -405,11 +405,17 @@ jumbo_static_library("rest_of_sync") {
     "//components/variations/net",
     "//services/network/public/cpp",
     "//sql",
+    "//third_party/cacheinvalidation",
     "//third_party/crc32c",
     "//third_party/zlib/google:compression_utils",
     "//ui/base",
   ]
 
+  if (is_android) {
+    deps += [ "//components/sync/android:jni_headers" ]
+    sources += [ "android/model_type_helper.cc" ]
+  }
+
   configs += [ "//build/config/compiler:wexit_time_destructors" ]
 }
 

components/sync/android/BUILD.gn

@@ -14,10 +14,13 @@ android_library("sync_java") {
     "//third_party/android_deps:androidx_annotation_annotation_java",
     "//third_party/android_deps:com_google_code_findbugs_jsr305_java",
     "//third_party/android_sdk:android_gcm_java",
+    "//third_party/cacheinvalidation:cacheinvalidation_javalib",
+    "//third_party/cacheinvalidation:cacheinvalidation_proto_java",
   ]
   annotation_processor_deps = [ "//base/android/jni_generator:jni_processor" ]
   srcjar_deps = [ ":java_enums" ]
   sources = [
+    "java/src/org/chromium/components/sync/ModelTypeHelper.java",
     "java/src/org/chromium/components/sync/Passphrase.java",
     "java/src/org/chromium/components/sync/SyncConstants.java",
     "java/src/org/chromium/components/sync/SyncContentResolverDelegate.java",
@@ -33,3 +36,7 @@ java_cpp_enum("java_enums") {
     "//components/sync/driver/sync_service_utils.h",
   ]
 }
+
+generate_jni("jni_headers") {
+  sources = [ "java/src/org/chromium/components/sync/ModelTypeHelper.java" ]
+}

components/sync/android/DEPS

@@ -2,4 +2,5 @@ include_rules = [
   "+components/signin/core/browser/android",
   "+components/sync/base",
   "+components/sync/test/android", # For sync test tools
+  "+third_party/cacheinvalidation",  # For imports in sync/notifier.
 ]

components/sync/android/java/src/org/chromium/components/sync/ModelTypeHelper.java

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.components.sync;
+
+import androidx.annotation.VisibleForTesting;
+
+import com.google.ipc.invalidation.external.client.types.ObjectId;
+import com.google.protos.ipc.invalidation.Types;
+
+import org.chromium.base.ApiCompatibilityUtils;
+import org.chromium.base.annotations.JNINamespace;
+import org.chromium.base.annotations.NativeMethods;
+
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Helper methods for dealing with ModelTypes.
+ *
+ * This class deals primarily with converting ModelTypes into notification types (string
+ * representations that are used to register for invalidations) and converting notification
+ * types into the actual ObjectIds used for invalidations.
+ *
+ */
+@JNINamespace("syncer")
+public class ModelTypeHelper {
+    /**
+     * Implement this class to override the behavior of
+     * {@link ModelTypeHelper#toNotificationType()} for tests.
+     */
+    public interface TestDelegate { public String toNotificationType(int modelType); }
+
+    private static final String TAG = "ModelTypeHelper";
+
+    private static final Object sLock = new Object();
+
+    private static final int[] NON_INVALIDATION_TYPES_ARRAY = new int[] {ModelType.PROXY_TABS};
+
+    private static TestDelegate sDelegate;
+
+    // Convenience sets for checking whether a type can have invalidations. Some ModelTypes
+    // such as PROXY_TABS are not real types and can't be registered. Initializing these
+    // once reduces toNotificationType() calls in the isInvalidationType() method.
+    private static Set<String> sNonInvalidationTypes;
+
+    /**
+     * Initializes the non-invalidation sets. Called lazily the first time they're needed.
+     */
+    private static void initNonInvalidationTypes() {
+        synchronized (sLock) {
+            if (sNonInvalidationTypes != null) return;
+
+            sNonInvalidationTypes = new HashSet<String>();
+            for (int i = 0; i < NON_INVALIDATION_TYPES_ARRAY.length; i++) {
+                sNonInvalidationTypes.add(toNotificationType(NON_INVALIDATION_TYPES_ARRAY[i]));
+            }
+        }
+    }
+
+    /**
+     * Checks whether a type is allowed to register for invalidations.
+     */
+    private static boolean isInvalidationType(String notificationType) {
+        initNonInvalidationTypes();
+        return !sNonInvalidationTypes.contains(notificationType);
+    }
+
+    /**
+     * Converts a notification type into an ObjectId.
+     *
+     * If the model type is not an invalidation type, this function uses the string "NULL".
+     */
+    private static ObjectId toObjectId(String notificationType) {
+        String objectIdString = isInvalidationType(notificationType) ? notificationType : "NULL";
+        return ObjectId.newInstance(
+                Types.ObjectSource.CHROME_SYNC, ApiCompatibilityUtils.getBytesUtf8(objectIdString));
+    }
+
+    @VisibleForTesting
+    public static ObjectId toObjectId(int modelType) {
+        return toObjectId(toNotificationType(modelType));
+    }
+
+    /**
+     * Converts a model type to its notification type representation using JNI.
+     *
+     * This is the value that is stored in the invalidation preferences and used to
+     * register for invalidations.
+     *
+     * @param modelType the model type to convert to a string.
+     * @return the string representation of the model type constant.
+     */
+    public static String toNotificationType(int modelType) {
+        if (sDelegate != null) return sDelegate.toNotificationType(modelType);
+
+        // Because PROXY_TABS isn't an invalidation type, it doesn't have a string from native,
+        // but for backwards compatibility we need to keep its pref value the same as the old
+        // ModelType enum name value.
+        if (modelType == ModelType.PROXY_TABS) {
+            return "PROXY_TABS";
+        }
+        return ModelTypeHelperJni.get().modelTypeToNotificationType(modelType);
+    }
+
+    /**
+     * Converts a set of {@link String} notification types to a set of {@link ObjectId}.
+     *
+     * This function assumes that all the strings passed in were generated with
+     * ModelTypeHelper.toNotificationType. Any notification types that are nonInvalidationTypes
+     * are filtered out.
+     */
+    public static Set<ObjectId> notificationTypesToObjectIds(Collection<String> notificationTypes) {
+        Set<ObjectId> objectIds = new HashSet<ObjectId>();
+        for (String notificationType : notificationTypes) {
+            if (isInvalidationType(notificationType)) {
+                objectIds.add(toObjectId(notificationType));
+            }
+        }
+        return objectIds;
+    }
+
+    @VisibleForTesting
+    public static void setTestDelegate(TestDelegate delegate) {
+        sDelegate = delegate;
+    }
+
+    @NativeMethods
+    interface Natives {
+        String modelTypeToNotificationType(int modelType);
+    }
+}

components/sync/android/model_type_helper.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <string>
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_string.h"
+#include "base/notreached.h"
+#include "components/sync/android/jni_headers/ModelTypeHelper_jni.h"
+#include "components/sync/base/model_type.h"
+
+using base::android::JavaParamRef;
+using base::android::ScopedJavaLocalRef;
+
+namespace syncer {
+
+static ScopedJavaLocalRef<jstring>
+JNI_ModelTypeHelper_ModelTypeToNotificationType(
+    JNIEnv* env,
+    jint model_type_int) {
+  std::string model_type_string;
+  ModelType model_type = static_cast<ModelType>(model_type_int);
+  if (!RealModelTypeToNotificationType(model_type, &model_type_string)) {
+    NOTREACHED() << "No string representation of model type " << model_type;
+  }
+  return base::android::ConvertUTF8ToJavaString(env, model_type_string);
+}
+
+}  // namespace syncer

components/sync/base/DEPS

@@ -7,6 +7,7 @@ include_rules = [
   "+components/reading_list/features",
   "+components/sync/protocol",
   "+components/sync_preferences",
+  "+google/cacheinvalidation",
   "+third_party/metrics_proto",
   "+third_party/zlib",  # For UniquePosition compression
   "+net",

components/sync/driver/DEPS

@@ -18,6 +18,7 @@ include_rules = [
   "+components/sync/protocol",
   "+components/sync/test",
   "+components/sync_preferences",
+  "+google/cacheinvalidation",
   "+net",
   "+policy",
   "+services/network/public/cpp",