Fix up _some_web app directory StrictMode violations

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

Index: base/android/java/src/org/chromium/base/FileUtils.java
diff --git a/base/android/java/src/org/chromium/base/FileUtils.java b/base/android/java/src/org/chromium/base/FileUtils.java
new file mode 100644
index 0000000000000000000000000000000000000000..75f11a15f67006320a5a481180277cb915984a25
--- /dev/null
+++ b/base/android/java/src/org/chromium/base/FileUtils.java
@@ -0,0 +1,34 @@
+// 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.base;
+
+import java.io.File;
+
+/**
+ * Helper methods for dealing with Files.
+ */
+public class FileUtils {
+    private static final String TAG = "FileUtils";
+
+    /**
+     * Delete the given File and (if it's a directory) everything within it.
+     */
+    public static void recursivelyDeleteFile(File currentFile) {
+        if (currentFile.isDirectory()) {

[Yaron, 2015/09/22 20:28:08]

Assert that we aren't on UI thread?

[gone, 2015/09/23 11:07:03]

Done.

+            File[] files = currentFile.listFiles();
+            if (files != null) {
+                for (File file : files) {
+                    recursivelyDeleteFile(file);
+                }
+            }
+        }
+
+        try {
+            if (!currentFile.delete()) Log.e(TAG, "Failed to delete: " + currentFile);
+        } catch (SecurityException e) {

[Yaron, 2015/09/22 20:28:08]

Why is this added? Have you seen it?

[gone, 2015/09/23 11:07:03]

Was worried about Android M throwing a fit with the new permissions model.  I
haven't seen it in practice, but I wouldn't be surprised if we end up seeing
something about it at some point in the crash stacks.  Can be swayed to take it
out but it seems safer to keep it, given that the API docs mention it can
happen.

[Yaron, 2015/09/24 18:31:01]

I don't see it in API docs. Perhaps I'm blind? I guess I'm fine with it staying.

+            Log.e(TAG, "Hit SecurityException when trying to delete: " + currentFile, e);
+        }
+    }
+}