Reland of Add increment install native libraries first in lookup paths

build/android/incremental_install/java/org/chromium/incrementalinstall/ClassLoaderPatcher.java

 // 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.incrementalinstall;
 
 import android.content.Context;
 import android.os.Build;
 import android.util.Log;
 
@@ skipping 76 matching lines @@
         }
 
         Log.i(TAG, "Code cache dir: " + optimizedDir);
         // TODO(agrieve): Might need to record classpath ordering if we ever have duplicate
         //     class names (since then order will matter here).
         Log.i(TAG, "Loading " + dexFilesArr.length + " dex files");
 
         Object dexPathList = Reflect.getField(mClassLoader, "pathList");
         Object[] dexElements = (Object[]) Reflect.getField(dexPathList, "dexElements");
         Object[] additionalElements = makeDexElements(dexFilesArr, optimizedDir);
-        Reflect.setField(
-                dexPathList, "dexElements", Reflect.concatArrays(dexElements, additionalElements));
+        Reflect.setField(dexPathList, "dexElements",
+                Reflect.concatArrays(dexElements, dexElements, additionalElements));
     }
 
     /**
      * Sets up all libraries within |libDir| to be loadable by System.loadLibrary().
      */
     void importNativeLibs(File libDir) throws ReflectiveOperationException, IOException {
         Log.i(TAG, "Importing native libraries from: " + libDir);
         if (!libDir.exists()) {
             Log.i(TAG, "No native libs exist.");
             return;
@@ skipping 34 matching lines @@
     }
 
     @SuppressWarnings("unchecked")
     private void addNativeLibrarySearchPath(File nativeLibDir) throws ReflectiveOperationException {
         Object dexPathList = Reflect.getField(mClassLoader, "pathList");
         Object currentDirs = Reflect.getField(dexPathList, "nativeLibraryDirectories");
         File[] newDirs = new File[] { nativeLibDir };
         // Switched from an array to an ArrayList in Lollipop.
         if (currentDirs instanceof List) {
             List<File> dirsAsList = (List<File>) currentDirs;
-            dirsAsList.add(nativeLibDir);
+            dirsAsList.add(0, nativeLibDir);
         } else {
             File[] dirsAsArray = (File[]) currentDirs;
             Reflect.setField(dexPathList, "nativeLibraryDirectories",
-                    Reflect.concatArrays(dirsAsArray, newDirs));
+                    Reflect.concatArrays(newDirs, newDirs, dirsAsArray));
         }
 
         Object[] nativeLibraryPathElements;
         try {
             nativeLibraryPathElements =
                     (Object[]) Reflect.getField(dexPathList, "nativeLibraryPathElements");
         } catch (NoSuchFieldException e) {
             // This field doesn't exist pre-M.
             return;
         }
         Object[] additionalElements = makeNativePathElements(newDirs);
-        Reflect.setField(
-                dexPathList, "nativeLibraryPathElements",
-                Reflect.concatArrays(nativeLibraryPathElements, additionalElements));
+        Reflect.setField(dexPathList, "nativeLibraryPathElements",
+                Reflect.concatArrays(nativeLibraryPathElements, additionalElements,
+                        nativeLibraryPathElements));
     }
 
     private static void copyChangedFiles(File srcDir, File dstDir) throws IOException {
         // No need to delete stale libs since libraries are loaded explicitly.
         int numNotChanged = 0;
         for (File f : srcDir.listFiles()) {
             // Note: Tried using hardlinks, but resulted in EACCES exceptions.
             File dest = new File(dstDir, f.getName());
             if (!copyIfModified(f, dest)) {
                 numNotChanged++;
@@ skipping 47 matching lines @@
         Object[] entries = new Object[files.length];
         File emptyDir = new File("");
         for (int i = 0; i < files.length; ++i) {
             File file = files[i];
             Object dexFile = Reflect.invokeMethod(clazz, "loadDexFile", file, optimizedDirectory);
             entries[i] = Reflect.newInstance(entryClazz, emptyDir, false, file, dexFile);
         }
         return entries;
     }
 }