Remove the enable_task_manager build flag and define.

chrome/browser/prerender/prerender_browsertest.cc

Index: chrome/browser/prerender/prerender_browsertest.cc
diff --git a/chrome/browser/prerender/prerender_browsertest.cc b/chrome/browser/prerender/prerender_browsertest.cc
index 345bfaf4f54d418898184f722a25f46f2f3b0168..4cc65f26f0c70fb3de78db9414da5ce985288869 100644
--- a/chrome/browser/prerender/prerender_browsertest.cc
+++ b/chrome/browser/prerender/prerender_browsertest.cc
@@ -1764,7 +1764,7 @@ IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, PrerenderAbortPendingOnCancel) {
   EXPECT_TRUE(IsEmptyPrerenderLinkManager());
 }
 
-#if defined(ENABLE_TASK_MANAGER)
+#if !defined(OS_ANDROID)
 
 IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, OpenTaskManagerBeforePrerender) {
   const base::string16 any_prerender = MatchTaskManagerPrerender("*");
@@ -1855,7 +1855,7 @@ IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, OpenTaskManagerAfterSwapIn) {
   ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(0, any_prerender));
 }
 
-#endif  // defined(ENABLE_TASK_MANAGER)
+#endif  // !defined(OS_ANDROID)
 
 // Checks that audio loads are deferred on prerendering.
 IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, PrerenderHTML5Audio) {