content: Re-enable ChildDiscardableSharedMemoryManager browser tests on ChromeOS.

content/child/child_discardable_shared_memory_manager_browsertest.cc

Index: content/child/child_discardable_shared_memory_manager_browsertest.cc
diff --git a/content/child/child_discardable_shared_memory_manager_browsertest.cc b/content/child/child_discardable_shared_memory_manager_browsertest.cc
index 18598fbdbb0e3818ab0574a1ec32069178f952c9..e4610f6d482aefcc0643a3baa973a843fcf30844 100644
--- a/content/child/child_discardable_shared_memory_manager_browsertest.cc
+++ b/content/child/child_discardable_shared_memory_manager_browsertest.cc
@@ -15,16 +15,11 @@
 
 namespace content {
 
-// ChromeOS does not do software compositing, so kDisableGpu is not available
-// there.
-#if !defined(OS_CHROMEOS)
-
 class ChildDiscardableSharedMemoryManagerBrowserTest
     : public ContentBrowserTest {
  public:
   void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitch(switches::kSingleProcess);
-    command_line->AppendSwitch(switches::kDisableGpu);
   }
 
   static void ReleaseFreeMemory() {
@@ -122,6 +117,4 @@ IN_PROC_BROWSER_TEST_F(ChildDiscardableSharedMemoryManagerBrowserTest,
   }
 }
 
-#endif  // !OS_CHROMEOS
-
 }  // content