Remove redundant OS_CHROMEOS checks

The OS_CHROMEOS define implies OS_LINUX. So a preprocessor conditional like:
    if defined(OS_LINUX) || defined(OS_CHROMEOS)
is redundant and should just be:
    if defined(OS_LINUX).

Bug: 290185 (kind of)
Change-Id: I382c636d2641ae95b2a00516fbfd3a494640a9fb
Reviewed-on: https://chromium-review.googlesource.com/534776
Reviewed-by: Brett Wilson <[email protected]>
Reviewed-by: Dan Erat <[email protected]>
Commit-Queue: Michael Giuffrida <[email protected]>
Cr-Commit-Position: refs/heads/master@{#491356}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index e1ac7d3e..051a5bb8 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -892,8 +892,7 @@
         {"Learning", kSpeculativeResourcePrefetchingLearning,
          arraysize(kSpeculativeResourcePrefetchingLearning), nullptr}};
 
-#if defined(OS_CHROMEOS) || defined(OS_LINUX) || defined(OS_MACOSX) || \
-    defined(OS_WIN)
+#if defined(OS_LINUX) || defined(OS_MACOSX) || defined(OS_WIN)
 const FeatureEntry::FeatureParam kPauseBackgroundTabsMinimalEngagment[] = {
     {pausetabs::kFeatureName, pausetabs::kModeParamMinimal}};
 
@@ -1821,12 +1820,12 @@
      ENABLE_DISABLE_VALUE_TYPE(switches::kEnableTranslateNewUX,
                                switches::kDisableTranslateNewUX)},
 #endif  // OS_MACOSX
-#if defined(OS_LINUX) || defined(OS_WIN) || defined(OS_CHROMEOS)
+#if defined(OS_LINUX) || defined(OS_WIN)
     {"translate-2016q2-ui", flag_descriptions::kTranslate2016q2UiName,
      flag_descriptions::kTranslate2016q2UiDescription,
      kOsCrOS | kOsWin | kOsLinux,
      FEATURE_VALUE_TYPE(translate::kTranslateUI2016Q2)},
-#endif  // OS_LINUX || OS_WIN || OS_CHROMEOS
+#endif  // OS_LINUX || OS_WIN
     {"translate-lang-by-ulp", flag_descriptions::kTranslateLanguageByUlpName,
      flag_descriptions::kTranslateLanguageByUlpDescription, kOsAll,
      FEATURE_VALUE_TYPE(translate::kTranslateLanguageByULP)},
@@ -2915,8 +2914,7 @@
      flag_descriptions::kNewOmniboxAnswerTypesDescription, kOsAll,
      FEATURE_VALUE_TYPE(omnibox::kNewOmniboxAnswerTypes)},
 
-#if defined(OS_CHROMEOS) || defined(OS_LINUX) || defined(OS_MACOSX) || \
-    defined(OS_WIN)
+#if defined(OS_LINUX) || defined(OS_MACOSX) || defined(OS_WIN)
     {"omnibox-entity-suggestions",
      flag_descriptions::kOmniboxEntitySuggestionsName,
      flag_descriptions::kOmniboxEntitySuggestionsDescription, kOsDesktop,
@@ -2927,8 +2925,7 @@
     {"enable-new-app-menu-icon", flag_descriptions::kEnableNewAppMenuIconName,
      flag_descriptions::kEnableNewAppMenuIconDescription, kOsDesktop,
      SINGLE_VALUE_TYPE(switches::kEnableNewAppMenuIcon)},
-#endif  // defined(OS_CHROMEOS) || defined(OS_LINUX) || defined(OS_MACOSX) ||
-        // defined(OS_WIN)
+#endif  // defined(OS_LINUX) || defined(OS_MACOSX) || defined(OS_WIN)
 
 #if defined(OS_ANDROID)
     {"enable-custom-feedback-ui",
@@ -2995,8 +2992,7 @@
      FEATURE_VALUE_TYPE(chrome::android::kCustomContextMenu)},
 #endif  // OS_ANDROID
 
-#if defined(OS_CHROMEOS) || defined(OS_LINUX) || defined(OS_MACOSX) || \
-    defined(OS_WIN)
+#if defined(OS_LINUX) || defined(OS_MACOSX) || defined(OS_WIN)
     {pausetabs::kFeatureName, flag_descriptions::kPauseBackgroundTabsName,
      flag_descriptions::kPauseBackgroundTabsDescription, kOsDesktop,
      FEATURE_WITH_PARAMS_VALUE_TYPE(pausetabs::kFeature,