Make it possible to build url/ without ICU on android.

url/url_canon_icu_alternatives_android.cc

+// Copyright 2014 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.h>
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_string.h"
+#include "base/strings/string16.h"
+#include "base/strings/string_piece.h"
+#include "jni/IDNStringUtil_jni.h"
+#include "url/url_canon_internal.h"
+
+namespace url {
+
+bool IDNToASCII(const base::char16* src, int src_len, CanonOutputW* output) {
+  DCHECK_EQ(0, output->length());  // Output buffer is assumed empty.
+
+  // An empty string is returned from Java both in the case of error and when
+  // the input string is of length 0.  Handle the 0-length input case here to
+  // avoid any confusion.
+  if (src_len == 0)
+    return true;
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  base::android::ScopedJavaLocalRef<jstring> java_src =
+      base::android::ConvertUTF16ToJavaString(
+          env, base::StringPiece16(src, src_len));
+  ScopedJavaLocalRef<jstring> java_result =
+      android::Java_IDNStringUtil_idnToASCII(env, java_src.obj());
+  base::string16 utf16_result =
+      base::android::ConvertJavaStringToUTF16(java_result);
+  output->Append(utf16_result.data(), static_cast<int>(utf16_result.size()));
+  return output->length() != 0;
+}
+
+bool RegisterIcuAlternativesJni(JNIEnv* env) {
+  return android::RegisterNativesImpl(env);
+}
+
+}  // namespace url