weblayer: adds strictmode for WebViewCompatibilityTest

Loading WebView loads from disk.

BUG=1062554
TEST=test only change

Change-Id: I156a8df429cce7b3f88827ed432ce1d3581c98ad
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2109132Reviewed-by: Clark DuVall <cduvall@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#751508}

weblayer/browser/android/javatests/src/org/chromium/weblayer/test/WebViewCompatibilityTest.java

@@ -13,6 +13,7 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
+import org.chromium.base.StrictModeContext;
 import org.chromium.base.test.util.CallbackHelper;
 import org.chromium.content_public.browser.test.util.TestThreadUtils;
 import org.chromium.weblayer.WebLayer;
@@ -35,8 +36,12 @@ public class WebViewCompatibilityTest {
                     InstrumentationRegistry.getTargetContext().getApplicationContext());
         });
         mActivityTestRule.launchShellWithUrl(mActivityTestRule.getTestDataURL("simple_page.html"));
-        WebView webView = TestThreadUtils.runOnUiThreadBlocking(
-                () -> { return new WebView(mActivityTestRule.getActivity()); });
+        WebView webView = TestThreadUtils.runOnUiThreadBlocking(() -> {
+            // Loading WebView triggers loading from disk.
+            try (StrictModeContext ignored = StrictModeContext.allowDiskReads()) {
+                return new WebView(mActivityTestRule.getActivity());
+            }
+        });
         CallbackHelper callbackHelper = new CallbackHelper();
         TestThreadUtils.runOnUiThreadBlocking(() -> {
             webView.setWebViewClient(new WebViewClient() {