Disable flaky test.

TabCapturePerformanceTest.Performance is flaky across multiple CQ
builders.

Bug: 1042457
Change-Id: I7fd59ac696c6bac0fcb27a860a06664016217749
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2003910
Commit-Queue: Yuri Wiitala <miu@chromium.org>
Reviewed-by: Yuri Wiitala <miu@chromium.org>
Auto-Submit: Sajjad Mirza <sajjadm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#733018}

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

@@ -277,6 +277,10 @@ class TabCapturePerformanceTest : public TabCapturePerformanceTestBase,
 }  // namespace
 
 IN_PROC_BROWSER_TEST_P(TabCapturePerformanceTest, Performance) {
+  if (!is_full_performance_run()) {
+    // TODO(crbug.com/1042457): Flaky failures across multiple CQ builders.
+    return;
+  }
   // Load the extension and test page, and tell the extension to start tab
   // capture.
   LoadExtension(GetApiTestDataDir()