aw: Use async upload by default

android_webview/lib/main/aw_main_delegate.cc

 // Copyright (c) 2012 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.
 
 #include "android_webview/lib/main/aw_main_delegate.h"
 
 #include "android_webview/browser/aw_content_browser_client.h"
 #include "android_webview/browser/browser_view_renderer.h"
 #include "android_webview/browser/gpu_memory_buffer_factory_impl.h"
 #include "android_webview/browser/scoped_allow_wait_for_legacy_web_view_api.h"
@@ skipping 35 matching lines @@
 
 AwMainDelegate::~AwMainDelegate() {
 }
 
 bool AwMainDelegate::BasicStartupComplete(int* exit_code) {
   content::SetContentClient(&content_client_);
 
   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) &&

[hush (inactive), 2014/08/11 17:12:49]

we have both kEnableZeroCopy and kDisableZeroCopy in content_switches.cc

This seems redundant, and confusing if you pass both options in the command
line.

But it seems both options are used in content/ folder. What's the point?
Can we keep kDisableZeroCopy and remove kEnableZeroCopy?

[boliu, 2014/08/11 17:15:06]

The rule is always disable trumps enable.
I don't actually know. I'd guess it probably has something to do with running
experiments and easily flipping the default case.
Ehh, follow up clean up

[hush (inactive), 2014/08/11 17:38:51]

Seems like content owners added it on purpose in this CL:
https://codereview.chromium.org/236313006
On 2014/08/11 17:15:06, boliu wrote:

                        gpu_memory_buffer_factory_.get()->Initialize();
 
   if (use_zero_copy) {
     cl->AppendSwitch(switches::kEnableZeroCopy);
   } else if (!zero_copy_disabled_by_switch) {
     cl->AppendSwitch(switches::kDisableZeroCopy);
   }
 
   content::BrowserMediaPlayerManager::RegisterMediaUrlInterceptor(
       new AwMediaUrlInterceptor());
@@ skipping 92 matching lines @@
 
 #if defined(VIDEO_HOLE)
 content::ExternalVideoSurfaceContainer*
 AwMainDelegate::CreateExternalVideoSurfaceContainer(
     content::WebContents* web_contents) {
   return new ExternalVideoSurfaceContainerImpl(web_contents);
 }
 #endif
 
 }  // namespace android_webview