[Android] Remove the workaround code of a platform bug.

base/android/java/src/org/chromium/base/library_loader/LibraryLoaderHelper.java

Index: base/android/java/src/org/chromium/base/library_loader/LibraryLoaderHelper.java
diff --git a/base/android/java/src/org/chromium/base/library_loader/LibraryLoaderHelper.java b/base/android/java/src/org/chromium/base/library_loader/LibraryLoaderHelper.java
index c185fadbe5f4b00a558ed863ead1abfc56d09948..14c99d5500e381077114b2a9d68fd0ccd2280abf 100644
--- a/base/android/java/src/org/chromium/base/library_loader/LibraryLoaderHelper.java
+++ b/base/android/java/src/org/chromium/base/library_loader/LibraryLoaderHelper.java
@@ -19,7 +19,6 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -44,94 +43,16 @@ class UnpackingException extends Exception {
 /**
  * The class provides helper functions to extract native libraries from APK,
  * and load libraries from there.
- *
- * The class should be package-visible only, but made public for testing
- * purpose.
  */
-public class LibraryLoaderHelper {
+class LibraryLoaderHelper {
     private static final String TAG = "LibraryLoaderHelper";
 
-    // Workaround and fallback directories.
-    // TODO(petrcermak): Merge the directories once refactored.
-    public static final String PACKAGE_MANAGER_WORKAROUND_DIR = "lib";
-    public static final String LOAD_FROM_APK_FALLBACK_DIR = "fallback";
+    // Fallback directories.
+    static final String LOAD_FROM_APK_FALLBACK_DIR = "fallback";

[rmcilroy, 2014/11/26 11:55:53]

nit - could you make this "fallback-lib" instead 

[Feng Qian, 2014/11/26 22:07:16]

If there are clients already use 'fallback', we need extra steps to cleanup the
old fallback libs.
The benefit might be far less than the extra code complexity introduced.

We should add a UMA stats to track how many users are using fallback libraries.
If there is none, we are safe to rename.

[rmcilroy, 2014/11/26 23:05:53]

We do have UMA (ChromiumAndroidLinker.LibraryLoadFromApkStatus) and no clients
are currently using the fallback, but I agree it's not worth adding code to deal
with this.

 
     private static final int BUFFER_SIZE = 16384;
 
     /**
-     * One-way switch becomes true if native libraries were unpacked
-     * from APK.
-     */
-    private static boolean sLibrariesWereUnpacked = false;
-
-    /**
-     * Loads native libraries using workaround only, skip the library in system
-     * lib path. The method exists only for testing purpose.
-     * Caller must ensure thread safety of this method.
-     * @param context
-     */
-    public static boolean loadNativeLibrariesUsingWorkaroundForTesting(Context context) {
-        // Although tryLoadLibraryUsingWorkaround might be called multiple times,
-        // libraries should only be unpacked once, this is guaranteed by
-        // sLibrariesWereUnpacked.
-        for (String library : NativeLibraries.LIBRARIES) {
-            if (!tryLoadLibraryUsingWorkaround(context, library)) {
-                return false;
-            }
-        }
-        return true;
-    }
-
-    /**
-     * Try to load a native library using a workaround of
-     *   http://b/13216167.
-     *
-     * Workaround for b/13216167 was adapted from code in
-     * https://googleplex-android-review.git.corp.google.com/#/c/433061
-     *
-     * More details about http://b/13216167:
-     *   PackageManager may fail to update shared library.
-     *
-     * Native library directory in an updated package is a symbolic link
-     * to a directory in /data/app-lib/<package name>, for example:
-     * /data/data/com.android.chrome/lib -> /data/app-lib/com.android.chrome[-1].
-     * When updating the application, the PackageManager create a new directory,
-     * e.g., /data/app-lib/com.android.chrome-2, and remove the old symlink and
-     * recreate one to the new directory. However, on some devices (e.g. Sony Xperia),
-     * the symlink was updated, but fails to extract new native libraries from
-     * the new apk.
-     *
-     * We make the following changes to alleviate the issue:
-     *  1) name the native library with apk version code, e.g.,
-     *     libchrome.1750.136.so, 1750.136 is Chrome version number;
-     *  2) first try to load the library using System.loadLibrary,
-     *     if that failed due to the library file was not found,
-     *     search the named library in a /data/data/com.android.chrome/app_lib
-     *     directory. Because of change 1), each version has a different native
-     *     library name, so avoid mistakenly using the old native library.
-     *
-     *  If named library is not in /data/data/com.android.chrome/app_lib directory,
-     *  extract native libraries from apk and cache in the directory.
-     *
-     * This function doesn't throw UnsatisfiedLinkError, the caller needs to
-     * check the return value.
-     */
-    static boolean tryLoadLibraryUsingWorkaround(Context context, String library) {
-        assert context != null;
-        String libName = System.mapLibraryName(library);
-        File libFile = new File(getLibDir(context, PACKAGE_MANAGER_WORKAROUND_DIR), libName);
-        if (!libFile.exists() && !unpackWorkaroundLibrariesOnce(context)) {
-            return false;
-        }
-        try {
-            System.load(libFile.getAbsolutePath());
-            return true;
-        } catch (UnsatisfiedLinkError e) {
-            return false;
-        }
-    }
-
-    /**
      * Returns the directory for holding extracted native libraries.
      * It may create the directory if it doesn't exist.
      *
@@ -139,7 +60,7 @@ public class LibraryLoaderHelper {
      * @param dirName The name of the directory containing the libraries.
      * @return The directory file object.
      */
-    public static File getLibDir(Context context, String dirName) {
+    static File getLibDir(Context context, String dirName) {
         return context.getDir(dirName, Context.MODE_PRIVATE);
     }
 
@@ -150,46 +71,9 @@ public class LibraryLoaderHelper {
     }
 
     /**
-     * Unpack native libraries from the APK file. The method is supposed to
-     * be called only once. It deletes existing files in unpacked directory
-     * before unpacking.
-     *
-     * @param context
-     * @return true when unpacking was successful, false when failed or called
-     *         more than once.
-     */
-    private static boolean unpackWorkaroundLibrariesOnce(Context context) {
-        if (sLibrariesWereUnpacked) {
-            return false;
-        }
-        sLibrariesWereUnpacked = true;
-
-        deleteLibrariesSynchronously(context, PACKAGE_MANAGER_WORKAROUND_DIR);
-        File libDir = getLibDir(context, PACKAGE_MANAGER_WORKAROUND_DIR);
-
-        try {
-            Map<String, File> dstFiles = new HashMap<String, File>();
-            for (String library : NativeLibraries.LIBRARIES) {
-                String libName = System.mapLibraryName(library);
-                String pathInZipFile = getJniNameInApk(libName);
-                dstFiles.put(pathInZipFile, new File(libDir, libName));
-            }
-            unpackLibraries(context, dstFiles);
-            return true;
-        } catch (UnpackingException e) {
-            Log.e(TAG, "Failed to unpack native libraries", e);
-            deleteLibrariesSynchronously(context, PACKAGE_MANAGER_WORKAROUND_DIR);
-            return false;
-        }
-    }
-
-    /**
      * Delete libraries and their directory synchronously.
-     * For testing purpose only.
-     *
-     * @param context
      */
-    public static void deleteLibrariesSynchronously(Context context, String dirName) {
+    private static void deleteLibrariesSynchronously(Context context, String dirName) {
         File libDir = getLibDir(context, dirName);
         deleteObsoleteLibraries(libDir, Collections.<File>emptyList());
     }
@@ -197,8 +81,6 @@ public class LibraryLoaderHelper {
     /**
      * Delete libraries and their directory asynchronously.
      * The actual deletion is done in a background thread.
-     *
-     * @param context
      */
     static void deleteLibrariesAsynchronously(
             final Context context, final String dirName) {
@@ -220,7 +102,7 @@ public class LibraryLoaderHelper {
      * @param library Library name.
      * @return name of the fallback copy of the library.
      */
-    public static String buildFallbackLibrary(Context context, String library) {
+    static String buildFallbackLibrary(Context context, String library) {
         try {
             String libName = System.mapLibraryName(library);
             File fallbackLibDir = getLibDir(context, LOAD_FROM_APK_FALLBACK_DIR);