Back out r58711. It appears to have caused video/media-related ui_tests...

chrome/app/chrome_dll_main.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // TODO(port): the ifdefs in here are a first step towards trying to determine
 // the correct abstraction for all the OS functionality required at this
 // stage of process initialization. It should not be taken as a final
 // abstraction.
 
 #include "build/build_config.h"
@@ skipping 548 matching lines @@
   CHECK(signal(SIGPIPE, SIG_IGN) != SIG_ERR);
 #endif  // OS_POSIX
 
   if (parsed_command_line.HasSwitch(switches::kEnableNaCl)) {
     // NaCl currently requires two flags to run
     CommandLine* singleton_command_line = CommandLine::ForCurrentProcess();
     singleton_command_line->AppendSwitch(switches::kInternalNaCl);
     singleton_command_line->AppendSwitch(switches::kEnableGPUPlugin);
   }
 
-  // TODO(vangelis): Remove this block once accelerated compositing is enabled
-  // on all platforms.
-#if defined(OS_MACOSX)
-  // Accelerated compositing is currently disabled by default on the mac, as it
-  // is less stable than other platforms. We disable it by adding a disable
-  // to the command line switches. Note that the rest of the code only checks
-  // for the disable flag, never for enable.
-  if (!parsed_command_line.HasSwitch(
-      switches::kEnableAcceleratedCompositing)) {
-    CommandLine* singleton_command_line = CommandLine::ForCurrentProcess();
-    singleton_command_line->AppendSwitch(
-        switches::kDisableAcceleratedCompositing);
-  }
-#endif
-
 #if defined(OS_CHROMEOS)
   if (parsed_command_line.HasSwitch(switches::kBWSI)) {
     // Disable sync and extensions if we're in "browse without sign-in" mode.
     CommandLine* singleton_command_line = CommandLine::ForCurrentProcess();
     singleton_command_line->AppendSwitch(switches::kDisableSync);
     singleton_command_line->AppendSwitch(switches::kDisableExtensions);
     browser_defaults::bookmarks_enabled = false;
   }
 #endif
 
@@ skipping 355 matching lines @@
 
   logging::CleanupChromeLogging();
 
 #if defined(OS_MACOSX) && defined(GOOGLE_CHROME_BUILD)
   // TODO(mark): See the TODO(mark) above at InitCrashReporter.
   DestructCrashReporter();
 #endif  // OS_MACOSX && GOOGLE_CHROME_BUILD
 
   return rv;
 }