Add an utility class to improve java logs.

content/public/android/junit/src/org/chromium/base/LogTest.java

+// 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;

[Yaron, 2015/04/01 20:47:31]

This should be in a base/ folder if it's package base. If the problem is that
there only exists one at the content/ layer we should define a new one in base.
If this requires a test-apk on which to run (i.e. content_shell) then we can
still have lower layers (base,net,etc) roll up to content. This is what we
previously did with things like base_javatests

[dgn, 2015/04/02 12:47:20]

It's a unit test, no apk required to run it. I can maybe send a CL to enable
junit tests in //base, with this file as sample test? I will remove it from this
CL, and need it to land first then.

[Yaron, 2015/04/02 14:29:47]

Ok, sounds good

+
+import static org.junit.Assert.assertFalse;
+
+import org.chromium.testing.local.LocalRobolectricTestRunner;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.annotation.Config;
+
+@RunWith(LocalRobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class LogTest {
+    @Test(expected = IllegalArgumentException.class)
+    public void tooLongTagExceptionTest() {
+        new Log("OneCharTooLong!");
+    }
+
+    @Test
+    public void allowedTagsNoExceptionTest() {
+        // See android.util.Log#isLoggable(String, int)}'s doc.
+        final int maxAllowedTagLength = 23;
+        assertFalse(new Log(null).mTag.length() > maxAllowedTagLength);
+        assertFalse(new Log("").mTag.length() > maxAllowedTagLength);
+        assertFalse(new Log("Foo").mTag.length() > maxAllowedTagLength);
+        assertFalse(new Log("LongestAllowed").mTag.length() > maxAllowedTagLength);
+    }
+}