Add a StrictMode exclusion in UrlBar#onInitializeAccessibilityNodeInfo

Certain OEMs are triggering disk reads that are outside of our control.

BUG=640993

Review-Url: https://codereview.chromium.org/2271243004
Cr-Commit-Position: refs/heads/master@{#414476}

chrome/android/java/src/org/chromium/chrome/browser/omnibox/UrlBar.java

@@ -11,6 +11,7 @@ import android.content.res.Resources;
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.Rect;
+import android.os.StrictMode;
 import android.os.SystemClock;
 import android.text.Editable;
 import android.text.Layout;
@@ -961,7 +962,14 @@ public class UrlBar extends VerticallyFixedEditText {
 
     @Override
     public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
-        super.onInitializeAccessibilityNodeInfo(info);
+        // Certain OEM implementations of onInitializeAccessibilityNodeInfo trigger disk reads
+        // to access the clipboard.  crbug.com/640993
+        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
+        try {
+            super.onInitializeAccessibilityNodeInfo(info);
+        } finally {
+            StrictMode.setThreadPolicy(oldPolicy);
+        }
 
         if (mAccessibilityTextOverride != null) {
             info.setText(mAccessibilityTextOverride);