[Extensions] Re-enable the InvisibleIconBrowserAction test.

This test was disabled because it was flaky on ChromeOS. I ran
it for 3000 iterations on the bots and there were no flakes on
any platform.

Bug: 1019669
Change-Id: I7e4e7665375903d531e1fbfc9862b14e25b2c024
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2132602Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: David Bertoni <dbertoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755969}

chrome/browser/extensions/api/extension_action/browser_action_apitest.cc

@@ -454,14 +454,7 @@ IN_PROC_BROWSER_TEST_F(BrowserActionApiCanvasTest, DynamicBrowserAction) {
   EXPECT_EQ(kEmptyPathError, catcher.message());
 }
 
-// https://crbug.com/1019669; flaky on ChromeOS.
-#if defined(OS_CHROMEOS)
-#define MAYBE_InvisibleIconBrowserAction DISABLED_InvisibleIconBrowserAction
-#else
-#define MAYBE_InvisibleIconBrowserAction InvisibleIconBrowserAction
-#endif
-IN_PROC_BROWSER_TEST_F(BrowserActionApiCanvasTest,
-                       MAYBE_InvisibleIconBrowserAction) {
+IN_PROC_BROWSER_TEST_F(BrowserActionApiCanvasTest, InvisibleIconBrowserAction) {
   // Turn this on so errors are reported.
   ExtensionActionSetIconFunction::SetReportErrorForInvisibleIconForTesting(
       true);