Update from https://crrev.com/311346

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

Index: base/android/java/src/org/chromium/base/ResourceExtractor.java
diff --git a/base/android/java/src/org/chromium/base/ResourceExtractor.java b/base/android/java/src/org/chromium/base/ResourceExtractor.java
index 5beb07dcb8975cc6743c2a18894a7d3d6b41ba5c..9252b4dd37227fffb6a74fa9b96ee993b80d512e 100644
--- a/base/android/java/src/org/chromium/base/ResourceExtractor.java
+++ b/base/android/java/src/org/chromium/base/ResourceExtractor.java
@@ -23,7 +23,6 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.ArrayList;
-import java.util.HashSet;
 import java.util.List;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.ExecutionException;
@@ -37,7 +36,7 @@ public class ResourceExtractor {
 
     private static final String LOGTAG = "ResourceExtractor";
     private static final String LAST_LANGUAGE = "Last language";
-    private static final String PAK_FILENAMES = "Pak filenames";
+    private static final String PAK_FILENAMES_LEGACY_NOREUSE = "Pak filenames";
     private static final String ICU_DATA_FILENAME = "icudtl.dat";
     private static final String V8_NATIVES_DATA_FILENAME = "natives_blob.bin";
     private static final String V8_SNAPSHOT_DATA_FILENAME = "snapshot_blob.bin";
@@ -49,6 +48,12 @@ public class ResourceExtractor {
     // change this behavior.
     private static boolean sExtractImplicitLocalePak = true;
 
+    private static boolean isAppDataFile(String file) {
+        return ICU_DATA_FILENAME.equals(file)
+                || V8_NATIVES_DATA_FILENAME.equals(file)
+                || V8_SNAPSHOT_DATA_FILENAME.equals(file);
+    }
+
     private class ExtractTask extends AsyncTask<Void, Void, Void> {
         private static final int BUFFER_SIZE = 16 * 1024;
 
@@ -57,6 +62,7 @@ public class ResourceExtractor {
 
         private void doInBackgroundImpl() {
             final File outputDir = getOutputDir();
+            final File appDataDir = getAppDataDir();
             if (!outputDir.exists() && !outputDir.mkdirs()) {
                 Log.e(LOGTAG, "Unable to create pak resources directory!");
                 return;
@@ -74,16 +80,15 @@ public class ResourceExtractor {
             }
 
             SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(mContext);
-            HashSet<String> filenames = (HashSet<String>) prefs.getStringSet(
-                    PAK_FILENAMES, new HashSet<String>());
             String currentLocale = LocaleUtils.getDefaultLocale();
             String currentLanguage = currentLocale.split("-", 2)[0];
-
-            if (prefs.getString(LAST_LANGUAGE, "").equals(currentLanguage)
-                    && filenames.size() >= sMandatoryPaks.length) {
+            // If everything we need is already there (and the locale hasn't
+            // changed), quick exit.
+            if (prefs.getString(LAST_LANGUAGE, "").equals(currentLanguage)) {
                 boolean filesPresent = true;
-                for (String file : filenames) {
-                    if (!new File(outputDir, file).exists()) {
+                for (String file : sMandatoryPaks) {
+                    File directory = isAppDataFile(file) ? appDataDir : outputDir;
+                    if (!new File(directory, file).exists()) {
                         filesPresent = false;
                         break;
                     }
@@ -122,10 +127,7 @@ public class ResourceExtractor {
                     if (!paksToInstall.matcher(file).matches()) {
                         continue;
                     }
-                    boolean isAppDataFile = file.equals(ICU_DATA_FILENAME)
-                            || file.equals(V8_NATIVES_DATA_FILENAME)
-                            || file.equals(V8_SNAPSHOT_DATA_FILENAME);
-                    File output = new File(isAppDataFile ? getAppDataDir() : outputDir, file);
+                    File output = new File(isAppDataFile(file) ? appDataDir : outputDir, file);
                     if (output.exists()) {
                         continue;
                     }
@@ -152,9 +154,7 @@ public class ResourceExtractor {
                             throw new IOException(file + " extracted with 0 length!");
                         }
 
-                        if (!isAppDataFile) {
-                            filenames.add(file);
-                        } else {
+                        if (isAppDataFile(file)) {
                             // icu and V8 data need to be accessed by a renderer
                             // process.
                             output.setReadable(true, false);
@@ -194,9 +194,6 @@ public class ResourceExtractor {
                     Log.w(LOGTAG, "Failed to write resource pak timestamp!");
                 }
             }
-            // TODO(yusufo): Figure out why remove is required here.
-            prefs.edit().remove(PAK_FILENAMES).apply();
-            prefs.edit().putStringSet(PAK_FILENAMES, filenames).apply();
         }
 
         @Override