third_party/protobuf: Update to HEAD (f52e188fe4)

third_party/protobuf/java/core/src/main/java/com/google/protobuf/ExtensionRegistryFactory.java

Index: third_party/protobuf/java/core/src/main/java/com/google/protobuf/ExtensionRegistryFactory.java
diff --git a/third_party/protobuf/java/core/src/main/java/com/google/protobuf/ExtensionRegistryFactory.java b/third_party/protobuf/java/core/src/main/java/com/google/protobuf/ExtensionRegistryFactory.java
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+++ b/third_party/protobuf/java/core/src/main/java/com/google/protobuf/ExtensionRegistryFactory.java
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+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static com.google.protobuf.ExtensionRegistryLite.EMPTY_REGISTRY_LITE;
+
+/**
+ * A factory object to create instances of {@link ExtensionRegistryLite}.
+ * 
+ * <p>
+ * This factory detects (via reflection) if the full (non-Lite) protocol buffer libraries
+ * are available, and if so, the instances returned are actually {@link ExtensionRegistry}.
+ */
+final class ExtensionRegistryFactory {
+
+  static final String FULL_REGISTRY_CLASS_NAME = "com.google.protobuf.ExtensionRegistry";
+
+  /* Visible for Testing
+     @Nullable */
+  static final Class<?> EXTENSION_REGISTRY_CLASS = reflectExtensionRegistry();
+
+  /* @Nullable */
+  static Class<?> reflectExtensionRegistry() {
+    try {
+      return Class.forName(FULL_REGISTRY_CLASS_NAME);
+    } catch (ClassNotFoundException e) {
+      // The exception allocation is potentially expensive on Android (where it can be triggered
+      // many times at start up). Is there a way to ameliorate this?
+      return null;
+    }
+  }
+
+  /** Construct a new, empty instance. */
+  public static ExtensionRegistryLite create() {
+    if (EXTENSION_REGISTRY_CLASS != null) {
+      try {
+        return invokeSubclassFactory("newInstance");
+      } catch (Exception e) {
+        // return a Lite registry.
+      }
+    }
+    return new ExtensionRegistryLite();
+  }
+
+  /** Get the unmodifiable singleton empty instance. */
+  public static ExtensionRegistryLite createEmpty() {
+    if (EXTENSION_REGISTRY_CLASS != null) {
+      try {
+        return invokeSubclassFactory("getEmptyRegistry");
+      } catch (Exception e) {
+        // return a Lite registry.
+      }
+    }
+    return EMPTY_REGISTRY_LITE;
+  }
+
+  static boolean isFullRegistry(ExtensionRegistryLite registry) {
+    return EXTENSION_REGISTRY_CLASS != null
+        && EXTENSION_REGISTRY_CLASS.isAssignableFrom(registry.getClass());
+  }
+
+  private static final ExtensionRegistryLite invokeSubclassFactory(String methodName)
+      throws Exception {
+    return (ExtensionRegistryLite) EXTENSION_REGISTRY_CLASS
+        .getMethod(methodName).invoke(null);
+  }
+}