Disable TabCaptureApiTest.ApiTests due to high flake rate.

BUG=764464
TBR=jophba@chromium.org

Change-Id: I359f377c5b73f51c14ede790aafa540a90128414
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2443851Reviewed-by: Greg Thompson <grt@chromium.org>
Commit-Queue: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813105}

chrome/browser/extensions/api/tab_capture/tab_capture_apitest.cc

@@ -148,7 +148,8 @@ TEST(TabCaptureCaptureOffscreenTabTest, DetermineInitialSize) {
 }
 
 // Tests API behaviors, including info queries, and constraints violations.
-IN_PROC_BROWSER_TEST_F(TabCaptureApiTest, ApiTests) {
+// Disabled due to high flake rate; see https://crbug.com/764464.
+IN_PROC_BROWSER_TEST_F(TabCaptureApiTest, DISABLED_ApiTests) {
   AddExtensionToCommandLineAllowlist();
   ASSERT_TRUE(RunExtensionSubtest("tab_capture", "api_tests.html")) << message_;
 }