Refactor OS_LINUX preprocessor directive for LaCrOS effort.

Currently, ChromeOS defines the OS_LINUX directive as well as
OS_CHROMEOS.  We're working to separate these two, so we're
making the fact that OS_LINUX == OS_LINUX || OS_CHROMEOS
explicit.

This is changes for /chrome/browser/media/webrtc/webrtc_disable_encryption_flag_browsertest.cc

This CL was uploaded by git cl split.

R=hbos@chromium.org

Bug: 1110266
Change-Id: I0fc68995d831e7b6317f1b949c5bbf4298978702
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2371248
Auto-Submit: Sean McAllister <smcallis@google.com>
Reviewed-by: Henrik Boström <hbos@chromium.org>
Commit-Queue: Henrik Boström <hbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800981}

chrome/browser/media/webrtc/webrtc_disable_encryption_flag_browsertest.cc

@@ -50,9 +50,9 @@ class WebRtcDisableEncryptionFlagBrowserTest : public WebRtcTestBase {
 // TODO(crbug.com/910216): De-flake this for ChromeOs.
 // TODO(crbug.com/984879): De-flake this for ASAN/MSAN Linux.
 #if defined(OS_CHROMEOS) ||                                        \
-    (defined(OS_LINUX) && (defined(MEMORY_SANITIZER) || \
-      defined(ADDRESS_SANITIZER)) ||                  \
-    (defined(OS_WIN) && defined(ADDRESS_SANITIZER)))
+    ((defined(OS_LINUX) || defined(OS_CHROMEOS)) &&                \
+     (defined(MEMORY_SANITIZER) || defined(ADDRESS_SANITIZER))) || \
+    (defined(OS_WIN) && defined(ADDRESS_SANITIZER))
 #define MAYBE_VerifyEncryption DISABLED_VerifyEncryption
 #else
 #define MAYBE_VerifyEncryption VerifyEncryption