Don't build the task manager into Android builds.

chrome/browser/prefs/browser_prefs.cc

Index: chrome/browser/prefs/browser_prefs.cc
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 3a885def626255770a7bcd688967700d5d27c714..88919ec820d9b066065495f9a9de3bc079df51cf 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -123,7 +123,6 @@ void RegisterLocalState(PrefService* local_state) {
   ProfileInfoCache::RegisterPrefs(local_state);
   ProfileManager::RegisterPrefs(local_state);
   SSLConfigServiceManager::RegisterPrefs(local_state);
-  TaskManager::RegisterPrefs(local_state);
   WebCacheManager::RegisterPrefs(local_state);
 
 #if defined(ENABLE_CONFIGURATION_POLICY)
@@ -138,6 +137,10 @@ void RegisterLocalState(PrefService* local_state) {
   SafeBrowsingService::RegisterPrefs(local_state);
 #endif
 
+#if defined(ENABLE_TASK_MANAGER)
+  TaskManager::RegisterPrefs(local_state);
+#endif  // defined(ENABLE_TASK_MANAGER)
+
 #if defined(TOOLKIT_VIEWS)
   BrowserView::RegisterBrowserViewPrefs(local_state);
 #endif