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/browsing_data

This CL was uploaded by git cl split.

R=msramek@chromium.org

Bug: 1110266
Change-Id: Icfd15fa49634bc33820bed97f2af27285921d40c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2371219
Auto-Submit: Sean McAllister <smcallis@google.com>
Reviewed-by: Martin Šrámek <msramek@chromium.org>
Commit-Queue: Martin Šrámek <msramek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800879}

chrome/browser/browsing_data/chrome_browsing_data_remover_delegate_unittest.cc

@@ -143,11 +143,11 @@
 #include "components/user_manager/scoped_user_manager.h"
 #endif  // defined(OS_CHROMEOS)
 
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
 #include "chrome/common/chrome_paths.h"
 #include "components/crash/core/app/crashpad.h"
 #include "components/upload_list/crash_upload_list.h"
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)
 
 #if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "chrome/browser/extensions/mock_extension_special_storage_policy.h"
@@ -3120,7 +3120,7 @@ TEST_F(ChromeBrowsingDataRemoverDelegateTest, WipeOriginVerifierData) {
 }
 #endif  // defined(OS_ANDROID)
 
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
 TEST_F(ChromeBrowsingDataRemoverDelegateTest, WipeCrashData) {
 #if !defined(OS_CHROMEOS)
   // This test applies only when using a logfile of Crash uploads. Chrome Linux

chrome/browser/browsing_data/counters/cache_counter_browsertest.cc

@@ -131,7 +131,7 @@ class CacheCounterTest : public InProcessBrowserTest {
 
 // Tests that for the empty cache, the result is zero.
 // Flaky. See crbug.com/971650.
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
 #define MAYBE_Empty DISABLED_Empty
 #else
 #define MAYBE_Empty Empty