aw: Use async upload by default

BUG=399311

Review URL: https://codereview.chromium.org/459023002

Cr-Commit-Position: refs/heads/master@{#289252}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289252 0039d316-1c4b-4281-b951-d872f2087c98

android_webview/lib/main/aw_main_delegate.cc

@@ -53,6 +53,7 @@ bool AwMainDelegate::BasicStartupComplete(int* exit_code) {
   CommandLine* cl = CommandLine::ForCurrentProcess();
   bool zero_copy_disabled_by_switch = cl->HasSwitch(switches::kDisableZeroCopy);
   bool use_zero_copy = !zero_copy_disabled_by_switch &&
+                       cl->HasSwitch(switches::kEnableZeroCopy) &&
                        gpu_memory_buffer_factory_.get()->Initialize();
 
   if (use_zero_copy) {