Update //third_party/protobuf to version 3.

third_party/protobuf/java/src/main/java/com/google/protobuf/ExtensionLite.java

Index: third_party/protobuf/java/src/main/java/com/google/protobuf/ExtensionLite.java
diff --git a/third_party/protobuf/src/google/protobuf/unittest_optimize_for.proto b/third_party/protobuf/java/src/main/java/com/google/protobuf/ExtensionLite.java
similarity index 62%
copy from third_party/protobuf/src/google/protobuf/unittest_optimize_for.proto
copy to third_party/protobuf/java/src/main/java/com/google/protobuf/ExtensionLite.java
index feecbef8d4a90961b35be988402e49e74fed313c..f8f5bd2c4fd0c38436a99d2d0b3bb1f7bf5d3c87 100644
--- a/third_party/protobuf/src/google/protobuf/unittest_optimize_for.proto
+++ b/third_party/protobuf/java/src/main/java/com/google/protobuf/ExtensionLite.java
@@ -1,6 +1,6 @@
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
-// http://code.google.com/p/protobuf/
+// 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
@@ -28,34 +28,36 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Author: kenton@google.com (Kenton Varda)
-//  Based on original Protocol Buffers design by
-//  Sanjay Ghemawat, Jeff Dean, and others.
-//
-// A proto file which uses optimize_for = CODE_SIZE.
-
-import "google/protobuf/unittest.proto";
-
-package protobuf_unittest;
-
-option optimize_for = CODE_SIZE;
-
-message TestOptimizedForSize {
-  optional int32 i = 1;
-  optional ForeignMessage msg = 19;
-
-  extensions 1000 to max;
-
-  extend TestOptimizedForSize {
-    optional int32 test_extension = 1234;
-    optional TestRequiredOptimizedForSize test_extension2 = 1235;
+package com.google.protobuf;
+
+/**
+ * Lite interface that generated extensions implement.
+ * <p>
+ * Methods are for use by generated code only. You can hold a reference to
+ * extensions using this type name.
+ */
+public abstract class ExtensionLite<ContainingType extends MessageLite, Type> {
+
+  /** Returns the field number of the extension. */
+  public abstract int getNumber();
+
+  /** Returns the type of the field. */
+  public abstract WireFormat.FieldType getLiteType();
+
+  /** Returns whether it is a repeated field. */
+  public abstract boolean isRepeated();
+
+  /** Returns the default value of the extension field. */
+  public abstract Type getDefaultValue();
+
+  /**
+   * Returns the default instance of the extension field, if it's a message
+   * extension.
+   */
+  public abstract MessageLite getMessageDefaultInstance();
+  
+  /** Returns whether or not this extension is a Lite Extension. */
+  boolean isLite() {
+    return true;
   }
 }
-
-message TestRequiredOptimizedForSize {
-  required int32 x = 1;
-}
- 
-message TestOptionalOptimizedForSize {
-  optional TestRequiredOptimizedForSize o = 1;
-}