GN incremental_install: Enable lib copying for all devices

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 85 matching lines @@
         Object[] additionalElements = makeDexElements(dexFilesArr, optimizedDir);
         Reflect.setField(
                 dexPathList, "dexElements", Reflect.concatArrays(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 (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
-            libDir = prepareNativeLibsAndroidM(libDir);
-        }
-        addNativeLibrarySearchPath(libDir);
-    }
-
-    /**
-     * Primary process: Copies native libraries into the app's data directory
-     * Other processes: Waits for primary process to finish copying.
-     */
-    private File prepareNativeLibsAndroidM(File libDir) throws IOException {
+        // The library copying is not necessary on older devices, but we do it anyways to
+        // simplify things (it's fast compared to dexing).
+        // https://code.google.com/p/android/issues/detail?id=79480
         File localLibsDir = new File(mAppFilesSubDir, "lib");
         File copyLibsLockFile = new File(mAppFilesSubDir, "libcopy.lock");
         // Due to a new SELinux policy, all libs must be copied into the app's
         // data directory first.
         // https://code.google.com/p/android/issues/detail?id=79480
         if (mIsPrimaryProcess) {
             LockFile lockFile = LockFile.acquireRuntimeLock(copyLibsLockFile);
             if (lockFile == null) {
                 LockFile.waitForRuntimeLock(copyLibsLockFile, 10 * 1000);
             } else {
                 try {
                     ensureAppFilesSubDirExists();
                     localLibsDir.mkdir();
                     localLibsDir.setReadable(true, false);
                     localLibsDir.setExecutable(true, false);
                     copyChangedFiles(libDir, localLibsDir);
                 } finally {
                     lockFile.release();
                 }
             }
         } else {
-            // TODO: Work around this issue by using APK splits to install each dex / lib.
-            throw new RuntimeException("Incremental install does not work on Android M+ "
-                    + "with isolated processes. Use the gn arg:\n"
-                    + "    disable_incremental_isolated_processes=true\n"
-                    + "and try again.");
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+                // TODO: Work around this issue by using APK splits to install each dex / lib.
+                throw new RuntimeException("Incremental install does not work on Android M+ "
+                        + "with isolated processes. Use the gn arg:\n"
+                        + "    disable_incremental_isolated_processes=true\n"
+                        + "and try again.");
+            }
+            // Other processes: Waits for primary process to finish copying.
+            LockFile.waitForRuntimeLock(copyLibsLockFile, 10 * 1000);
         }
-        return localLibsDir;
+        addNativeLibrarySearchPath(localLibsDir);
     }
 
     @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;
@@ skipping 32 matching lines @@
         if (!dest.exists() || dest.lastModified() != lastModified) {
             Log.i(TAG, "Copying " + src + " -> " + dest);
             FileInputStream istream = new FileInputStream(src);
             FileOutputStream ostream = new FileOutputStream(dest);
             ostream.getChannel().transferFrom(istream.getChannel(), 0, istream.getChannel().size());
             istream.close();
             ostream.close();
             dest.setReadable(true, false);
             dest.setExecutable(true,  false);
             dest.setLastModified(lastModified);
+        } else {
+            Log.i(TAG, "Up-to-date: " + dest);
         }
     }
 
     private void ensureAppFilesSubDirExists() {
         mAppFilesSubDir.mkdir();
         mAppFilesSubDir.setExecutable(true, false);
     }
 
     private void createSymlink(String to, File from) throws ReflectiveOperationException {
         Reflect.invokeMethod(mLibcoreOs, "symlink", to, from.getAbsolutePath());
@@ skipping 16 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;
     }
 }