Disable DevToolsSanityTest.TestDeviceEmulation on Linux

TBR=estade@chromium.org

Bug: 990692
Change-Id: Ia2f8b62c2e9864b34c54ec8250d1718678366e4f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1737103Reviewed-by: Chris Sharp <csharp@chromium.org>
Commit-Queue: Chris Sharp <csharp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#684096}

chrome/browser/devtools/devtools_sanity_browsertest.cc

@@ -1593,7 +1593,13 @@ IN_PROC_BROWSER_TEST_F(DevToolsSanityTest, MAYBE_TestConsoleOnNavigateBack) {
   RunTest("testConsoleOnNavigateBack", kNavigateBackTestPage);
 }
 
-IN_PROC_BROWSER_TEST_F(DevToolsSanityTest, TestDeviceEmulation) {
+#if defined(OS_LINUX)
+// Flaking on linux runs, see crbug.com/990692.
+#define MAYBE_TestDeviceEmulation DISABLED_TestDeviceEmulation
+#else
+#define MAYBE_TestDeviceEmulation TestDeviceEmulation
+#endif
+IN_PROC_BROWSER_TEST_F(DevToolsSanityTest, MAYBE_TestDeviceEmulation) {
   RunTest("testDeviceMetricsOverrides", "about:blank");
 }