Put temp files within app files

Bug: 8715614
Change-Id: I307d83923070994525cf0d27aad403e881a89314

java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java

@@ -72,10 +72,16 @@ final class BinaryDictionaryGetter {
     public static String getTempFileName(final String id, final Context context)
             throws IOException {
         final String safeId = DictionaryInfoUtils.replaceFileNameDangerousCharacters(id);
+        final File directory = new File(DictionaryInfoUtils.getWordListTempDirectory(context));
+        if (!directory.exists()) {
+            if (!directory.mkdirs()) {
+                Log.e(TAG, "Could not create the temporary directory");
+            }
+        }
         // If the first argument is less than three chars, createTempFile throws a
         // RuntimeException. We don't really care about what name we get, so just
         // put a three-chars prefix makes us safe.
-        return File.createTempFile("xxx" + safeId, null).getAbsolutePath();
+        return File.createTempFile("xxx" + safeId, null, directory).getAbsolutePath();
     }
 
     /**

java/src/com/android/inputmethod/latin/DictionaryInfoUtils.java

@@ -128,6 +128,13 @@ public class DictionaryInfoUtils {
         return context.getFilesDir() + File.separator + "dicts";
     }
 
+    /**
+     * Helper method to get the top level temp directory.
+     */
+    public static String getWordListTempDirectory(final Context context) {
+        return context.getFilesDir() + File.separator + "tmp";
+    }
+
     /**
      * Reverse escaping done by replaceFileNameDangerousCharacters.
      */