Update jni_generator documentation removing GYP.

base/android/jni_generator/java/src/org/chromium/example/jni_generator/SampleForTests.java

 // Copyright 2012 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.example.jni_generator;
 
 import android.graphics.Rect;
 
 import org.chromium.base.annotations.AccessedByNative;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.CalledByNativeUnchecked;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.NativeClassQualifiedName;
 
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 
 // This class serves as a reference test for the bindings generator, and as example documentation
 // for how to use the jni generator.
 // The C++ counter-part is sample_for_tests.cc.
-// jni_generator.gyp has a jni_generator_tests target that will:
+// jni_generator/BUILD.gn has a jni_generator_tests target that will:
 //   * Generate a header file for the JNI bindings based on this file.
 //   * Compile sample_for_tests.cc using the generated header file.
 //   * link a native executable to prove the generated header + cc file are self-contained.
 // All comments are informational only, and are ignored by the jni generator.
 //
 // Binding C/C++ with Java is not trivial, specially when ownership and object lifetime
 // semantics needs to be managed across boundaries.
 // Following a few guidelines will make the code simpler and less buggy:
 //
 // - Never write any JNI "by hand". Rely on the bindings generator to have a thin
@@ skipping 262 matching lines @@
             // Now, do something with element.
             nativeAddStructB(mNativeCPPObject, element);
         }
         nativeIterateAndDoSomethingWithStructB(mNativeCPPObject);
     }
 
     native void nativeAddStructB(long nativeCPPClass, InnerStructB b);
     native void nativeIterateAndDoSomethingWithStructB(long nativeCPPClass);
     native String nativeReturnAString(long nativeCPPClass);
 }