Remove "not called from UI thread" check from NativeLibraryTestUtils

runOnUiThreadBlocking() has no restriction on being called from the
UI thread, so it should be safe to call the loadNativeLibrary...()
methods from the UI thread as well.

This CL also fixes one comment cross-reference to NativeLibraryTestRule,
which apparently doesn't exist anymore.


[1] https://source.chromium.org/chromium/chromium/src/+/master:base/android/java/src/org/chromium/base/ThreadUtils.java;drc=c741e070dbfcc33b2369e7a5131be87c7b21bb99;bpv=1;l=156

TBR=jdoerrie@chromium.org

Bug: None
Change-Id: Icd38029ac5dddd372485be00f03648068d7e3063
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2404351
Commit-Queue: Victor Vianna <victorvianna@google.com>
Reviewed-by: Victor Vianna <victorvianna@google.com>
Reviewed-by: Filip Gorski <fgorski@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807054}

base/test/android/javatests/src/org/chromium/base/test/util/Batch.java

@@ -44,7 +44,7 @@ public @interface Batch {
      * Unit tests must be careful not to persist any changes to global state, or flakes are likely
      * to occur.
      *
-     * An exception to this is loading Chrome's native library (eg. using NativeLibraryTestRule).
+     * An exception to this is loading Chrome's native library (eg. using NativeLibraryTestUtils).
      * Your unit tests must assume that the native library may have already been loaded by another
      * test.
      */

chrome/test/android/javatests/src/org/chromium/chrome/test/ChromeBrowserTestRule.java

@@ -26,9 +26,8 @@ public class ChromeBrowserTestRule implements TestRule {
             @Override
             public void evaluate() throws Throwable {
                 /**
-                 * Loads the native library on the activity UI thread (must not be called from the
-                 * UI thread).  After loading the library, this will initialize the browser process
-                 * if necessary.
+                 * Loads the native library on the activity UI thread.  After loading the library,
+                 * this will initialize the browser process if necessary.
                  */
                 NativeLibraryTestUtils.loadNativeLibraryAndInitBrowserProcess();
                 base.evaluate();

content/public/test/android/javatests/src/org/chromium/content_public/browser/test/NativeLibraryTestUtils.java

@@ -4,8 +4,6 @@
 
 package org.chromium.content_public.browser.test;
 
-import org.junit.Assert;
-
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.library_loader.LibraryLoader;
 import org.chromium.base.library_loader.LibraryProcessType;
@@ -18,14 +16,14 @@ import org.chromium.ui.resources.ResourceExtractor;
  */
 public class NativeLibraryTestUtils {
     /**
-     * Loads the native library on the activity UI thread (must not be called from the UI thread).
+     * Loads the native library on the activity UI thread.
      */
     public static void loadNativeLibraryNoBrowserProcess() {
         handleNativeInitialization(false);
     }
 
     /**
-     * Loads the native library on the activity UI thread (must not be called from the UI thread).
+     * Loads the native library on the activity UI thread.
      * After loading the library, this will initialize the browser process.
      */
     public static void loadNativeLibraryAndInitBrowserProcess() {
@@ -33,8 +31,6 @@ public class NativeLibraryTestUtils {
     }
 
     private static void handleNativeInitialization(final boolean initBrowserProcess) {
-        Assert.assertFalse(ThreadUtils.runningOnUiThread());
-
         // LibraryLoader is not in general multithreaded; as other InstrumentationTestCase code
         // (specifically, ChromeBrowserProvider) uses it from the main thread we must do
         // likewise.