[Android] Add gyp support for multidex.

base/android/java/src/org/chromium/base/multidex/ChromiumMultiDex.java

Index: base/android/java/src/org/chromium/base/multidex/ChromiumMultiDex.java
diff --git a/base/android/java/src/org/chromium/base/multidex/ChromiumMultiDex.java b/base/android/java/src/org/chromium/base/multidex/ChromiumMultiDex.java
new file mode 100644
index 0000000000000000000000000000000000000000..5b09865432d0c6ef40d49a0fe5552c39d48af78b
--- /dev/null
+++ b/base/android/java/src/org/chromium/base/multidex/ChromiumMultiDex.java
@@ -0,0 +1,56 @@
+// Copyright 2015 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.multidex;
+
+import android.content.Context;
+import android.os.Build;
+import android.os.Process;
+import android.support.multidex.MultiDex;
+
+import org.chromium.base.Log;
+
+import java.lang.reflect.InvocationTargetException;
+
+/**
+ *  Performs multidex installation for non-isolated processes.
+ */
+public class ChromiumMultiDex {
+
+    private static final String TAG = "cr.base.multidex";
+
+    /**
+     *  Installs secondary dexes if possible.
+     *
+     *  Isolated processes (e.g. renderer processes) can't load secondary dex files on
+     *  K and below, so we don't even try in that case.
+     *
+     *  @param context The application context.
+     */
+    public static void install(Context context) {
+        try {
+            // TODO(jbudorick): Back out this version check once support for K & below works.
+            // http://crbug.com/512357
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP && processIsIsolated()) {
+                Log.i(TAG, "Skipping multidex installation: inside isolated process.");
+            } else {
+                MultiDex.install(context);
+                Log.i(TAG, "Completed multidex installation.");
+            }
+        } catch (NoSuchMethodException e) {
+            Log.e(TAG, "Failed multidex installation", e);

[Yaron, 2015/08/05 21:56:41]

Won't be explode in this case? We're expecting multidex - if we can't load all
functions Bad Things will happen. Log.wtf or just fail harder?

[jbudorick, 2015/08/05 22:55:22]

It depends. The only way we hit these exception handlers is if the private API
call below fails in some way -- MultiDex.install doesn't throw these exceptions.
If we're in a renderer, we should be ok, as all of the renderer classes should
be in the main dex. If not, then we're dead.

[Yaron, 2015/08/10 20:15:40]

I think if the private API call fails, we should fail hard. It means our
expectations aren't satisfied and the next call will fail somehow but that could
be harder to see.

[Yaron, 2015/08/13 20:12:10]

bump

[jbudorick, 2015/08/14 21:01:21]

oops, lost this one.

Log.e -> Log.wtf

+        } catch (IllegalAccessException e) {
+            Log.e(TAG, "Failed multidex installation", e);
+        } catch (InvocationTargetException e) {
+            Log.e(TAG, "Failed multidex installation", e);
+        }
+    }
+
+    // Calls Process.isIsolated, a private Android API.
+    private static boolean processIsIsolated()
+            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
+        return (boolean) Process.class.getMethod("isIsolated").invoke(null);
+    }
+
+}