Revert "Disable flaky PerformanceManagerTabHelperTest.PageIsAudible"

This reverts commit fe93195d.

Reason for revert: This is a spurious failure caused by an
unrelated issue https://crbug.com/1012445. Individual test
should not be disabled because of this (a lot of tests are
affected -- it wouldn't make sense to disable all these 
tests because of a single problem).

Original change's description:
> Disable flaky PerformanceManagerTabHelperTest.PageIsAudible
> 
> TBR=fdoray
> 
> Bug: 1012601
> Change-Id: I9540e12715b4b431af0b886c280f609b51851b10
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1852429
> Reviewed-by: David Roger <droger@chromium.org>
> Commit-Queue: David Roger <droger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#704622}

TBR=droger@chromium.org,fdoray@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1012601
Change-Id: Icb00d26109eac1d532740b992acba94255c023a6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1872310Reviewed-by: François Doray <fdoray@chromium.org>
Commit-Queue: François Doray <fdoray@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707809}

components/performance_manager/performance_manager_tab_helper_unittest.cc

@@ -9,7 +9,6 @@
 #include "base/run_loop.h"
 #include "base/stl_util.h"
 #include "base/test/bind_test_util.h"
-#include "build/build_config.h"
 #include "components/performance_manager/graph/frame_node_impl.h"
 #include "components/performance_manager/graph/graph_impl_operations.h"
 #include "components/performance_manager/graph/page_node_impl.h"
@@ -219,13 +218,7 @@ void ExpectPageIsAudible(bool is_audible) {
 
 }  // namespace
 
-// This test is flaky on windows. See https://1012601
-#if defined(OS_WIN)
-#define MAYBE_PageIsAudible DISABLED_PageIsAudible
-#else
-#define MAYBE_PageIsAudible PageIsAudible
-#endif
-TEST_F(PerformanceManagerTabHelperTest, MAYBE_PageIsAudible) {
+TEST_F(PerformanceManagerTabHelperTest, PageIsAudible) {
   SetContents(CreateTestWebContents());
 
   ExpectPageIsAudible(false);