[headless] Fix window management browsertests on Mac.

headless/lib/headless_devtools_client_browsertest.cc

Index: headless/lib/headless_devtools_client_browsertest.cc
diff --git a/headless/lib/headless_devtools_client_browsertest.cc b/headless/lib/headless_devtools_client_browsertest.cc
index ab22e203028054522efada75f0bd8c0097e89e3e..0436a1966785cb06346cfec7ca44024768e21e68 100644
--- a/headless/lib/headless_devtools_client_browsertest.cc
+++ b/headless/lib/headless_devtools_client_browsertest.cc
@@ -146,8 +146,11 @@ class HeadlessDevToolsClientWindowManagementTest
       const browser::WindowState state,
       std::unique_ptr<browser::GetWindowBoundsResult> result) {
     const headless::browser::Bounds* actual_bounds = result->GetBounds();
+// https://crbug.com/726288: Mac does not currently support repositioning.
+#if !defined(OS_MACOSX)
     EXPECT_EQ(bounds.x(), actual_bounds->GetLeft());
     EXPECT_EQ(bounds.y(), actual_bounds->GetTop());
+#endif  // !defined(OS_MACOSX)
     EXPECT_EQ(bounds.width(), actual_bounds->GetWidth());
     EXPECT_EQ(bounds.height(), actual_bounds->GetHeight());
     EXPECT_EQ(state, actual_bounds->GetWindowState());