Whitelist another StrictMode violation.

It appears to do both a read and a write on KK. Whitelist the write.

BUG=527415
TBR=agrieve

Review URL: https://codereview.chromium.org/1345443002

Cr-Commit-Position: refs/heads/master@{#348614}
(cherry picked from commit b1068c5)

Review URL: https://codereview.chromium.org/1337993003 .

Cr-Commit-Position: refs/branch-heads/2490@{#242}
Cr-Branched-From: 7790a35-refs/heads/master@{#344925}

chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandler.java

@@ -254,6 +254,7 @@ private OverrideUrlLoadingResult shouldOverrideUrlLoadingInternal(
         boolean canResolveActivity = false;
         // Temporarily allowing disk access while fixing. TODO: http://crbug.com/527415
         StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
+        StrictMode.allowThreadDiskWrites();
         try {
             canResolveActivity = mDelegate.canResolveActivity(intent);
         } finally {