Update from https://crrev.com/333737

base/android/java/src/org/chromium/base/ApkAssets.java

Index: base/android/java/src/org/chromium/base/ApkAssets.java
diff --git a/base/android/java/src/org/chromium/base/ApkAssets.java b/base/android/java/src/org/chromium/base/ApkAssets.java
new file mode 100644
index 0000000000000000000000000000000000000000..329660f6216de0a212949ce545b93dddd85c91ff
--- /dev/null
+++ b/base/android/java/src/org/chromium/base/ApkAssets.java
@@ -0,0 +1,45 @@
+// 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.
+
+package org.chromium.base;
+
+import android.content.Context;
+import android.content.res.AssetFileDescriptor;
+import android.content.res.AssetManager;
+import android.util.Log;
+
+import java.io.IOException;
+
+/**
+ * A utility class to retrieve references to uncompressed assets insides the apk. A reference is
+ * defined as tuple (file descriptor, offset, size) enabling direct mapping without deflation.
+ * This can be used even within the renderer process, since it just dup's the apk's fd.
+ */
+@JNINamespace("base::android")
+public class ApkAssets {
+    private static final String LOGTAG = "ApkAssets";
+
+    @CalledByNative
+    public static long[] open(Context context, String fileName) {
+        AssetFileDescriptor afd = null;
+        try {
+            AssetManager manager = context.getAssets();
+            afd = manager.openNonAssetFd(fileName);
+            return new long[] { afd.getParcelFileDescriptor().detachFd(),
+                                afd.getStartOffset(),
+                                afd.getLength() };
+        } catch (IOException e) {
+            Log.e(LOGTAG, "Error while loading asset " + fileName + ": " + e);
+            return new long[] {-1, -1, -1};
+        } finally {
+            try {
+                if (afd != null) {
+                    afd.close();
+                }
+            } catch (IOException e2) {
+                Log.e(LOGTAG, "Unable to close AssetFileDescriptor", e2);
+            }
+        }
+    }
+}