pdf: Prepare tests for enabling annotations feature

Bug: 902646
Change-Id: I69015588df66c1d80817c141580f9fc29b248ece
Reviewed-on: https://chromium-review.googlesource.com/c/1482354
Commit-Queue: dstockwell <dstockwell@chromium.org>
Commit-Queue: Darren Shen <shend@chromium.org>
Auto-Submit: dstockwell <dstockwell@chromium.org>
Reviewed-by: Darren Shen <shend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634554}

chrome/test/data/pdf/annotations_feature_disabled_test.js

@@ -5,8 +5,11 @@
 chrome.test.runTests([
   function testAnnotationsDisabled() {
     const toolbar = document.body.querySelector('#toolbar');
-    chrome.test.assertFalse(toolbar.pdfAnnotationsEnabled);
-    chrome.test.assertEq(null, toolbar.shadowRoot.querySelector('#annotate'));
+    if (toolbar.pdfAnnotationsEnabled) {
+      chrome.test.assertTrue(!!toolbar.shadowRoot.querySelector('#annotate'));
+    } else {
+      chrome.test.assertFalse(!!toolbar.shadowRoot.querySelector('#annotate'));
+    }
     chrome.test.succeed();
   },
 ]);

chrome/test/data/pdf/basic_test.js

@@ -45,7 +45,7 @@ var tests = [
     chrome.test.assertTrue(shouldIgnoreKeyEvents(toolbar));
 
     // Test case where the active element has a shadow root of its own.
-    toolbar.$.buttons.children[1].focus();
+    toolbar.$['rotate-right'].focus();
     chrome.test.assertFalse(shouldIgnoreKeyEvents(toolbar));
 
     chrome.test.assertFalse(