[Extensions] Re-enable some Declarative Web Request API tests.

These tests were disabled on Mac ASAN for flakiness, due to
bug 496955. That bug has been fixed and these tests are no
longer flaky.

Bug: 851854, 496955
Change-Id: Idd52325c2103cb5518dc058242abeb27c1107451
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2238339Reviewed-by: Archana Simha <archanasimha@chromium.org>
Commit-Queue: David Bertoni <dbertoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#779072}

chrome/browser/extensions/api/declarative/declarative_apitest.cc

@@ -199,18 +199,9 @@ IN_PROC_BROWSER_TEST_F(DeclarativeApiTest, PersistRules) {
   EXPECT_EQ(kTestTitle, GetTitle());
 }
 
-// Disabled for flakiness: http://crbug.com/851854
-#if defined(OS_MACOSX) && defined(ADDRESS_SANITIZER)
-#define MAYBE_ExtensionLifetimeRulesHandling \
-  DISABLED_ExtensionLifetimeRulesHandling
-#else
-#define MAYBE_ExtensionLifetimeRulesHandling ExtensionLifetimeRulesHandling
-#endif
-
 // Test that the rules are correctly persisted and (de)activated during
 // changing the "installed" and "enabled" status of an extension.
-IN_PROC_BROWSER_TEST_F(DeclarativeApiTest,
-                       MAYBE_ExtensionLifetimeRulesHandling) {
+IN_PROC_BROWSER_TEST_F(DeclarativeApiTest, ExtensionLifetimeRulesHandling) {
   TestExtensionDir ext_dir;
 
   // 1. Install the extension. Rules should become active.
@@ -276,17 +267,10 @@ IN_PROC_BROWSER_TEST_F(DeclarativeApiTest,
   EXPECT_EQ(0u, NumberOfRegisteredRules(extension_id));
 }
 
-// Disabled for flakiness: http://crbug.com/851854
-#if defined(OS_MACOSX) && defined(ADDRESS_SANITIZER)
-#define MAYBE_NoTracesAfterUninstalling DISABLED_NoTracesAfterUninstalling
-#else
-#define MAYBE_NoTracesAfterUninstalling NoTracesAfterUninstalling
-#endif
-
 // When an extension is uninstalled, the state store deletes all preferences
 // stored for that extension. We need to make sure we don't store anything after
 // that deletion occurs.
-IN_PROC_BROWSER_TEST_F(DeclarativeApiTest, MAYBE_NoTracesAfterUninstalling) {
+IN_PROC_BROWSER_TEST_F(DeclarativeApiTest, NoTracesAfterUninstalling) {
   TestExtensionDir ext_dir;
 
   // 1. Install the extension. Verify that rules become active and some prefs