Enable WebAudio support on Android/x86.

Enable WebAudio support on Android/x86.

WebAudio support itself is disabled by default and can be enabled
using a flag in chrome://flags.  When so enabled, WebAudio will run.

BUG=290622, 292922
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=239518

[Raymond Toy (Google), 2013-11-20 23:12:29]

Xingnan, PTAL.

This isn't quite ready because I want to apply this after the ARM non-NEON CL
has landed, but that should only be a tiny change to runtime_features.cc.

But you should be able to apply this to the current tree and verify that
webaudio works. I tried this on an old phone and a simple oscillator works. I
couldn't try other demos because the phone is too old to support the MediaCodec
API.

[Raymond Toy (Google), 2013-11-22 22:29:59]

PTAL.

I've tested this CL on Android x86 devices to check that WebAudio can be enabled
and disabled. I verified that Android ARM devices still have WebAudio enabled by
default.  Finally, a quick test on Linux shows that no extra about:flags entries
have been introduced.

[Raymond Toy (Google), 2013-11-22 22:32:01]

PTAL.

I've verifed this on Android/x86 devices to see that WebAudio is disabled by
default, and tested that WebAudio runs on these devices if MediaCodec is
available.  For ARM devices, I verified that WebAudio is still enabled by
default and that everything works.  Finally, a quick check on Linux shows that
no extra about:flags entries have been introduced.

[xwang, 2013-11-23 14:52:51]

On 2013/11/22 22:32:01, rtoy wrote:
> PTAL.
> 
> I've verifed this on Android/x86 devices to see that WebAudio is disabled by
> default, and tested that WebAudio runs on these devices if MediaCodec is
> available.  For ARM devices, I verified that WebAudio is still enabled by
> default and that everything works.  Finally, a quick check on Linux shows that
> no extra about:flags entries have been introduced.

Hi Ray,

Sorry for the late response, I am being out of office. I will be back to the
company at the day after tomorrow and after that I will verify and test the
patch ASAP.
Code aside, LGTM.
One quick question, why we cannot support web audio on android webview now ?

[xwang, 2013-11-25 10:41:37]

Ray, 

It seems there is not enough source code outside Google to build chromium/chrome
browser on Android, what I can do is to build a content shell, in which I cannot
verified the about flags. But I verified your patch by enabling the flag by
default on several x86 phones, web audio works well. Maybe some of your Google
guys can help verify the flags. From my side, the patch looks good. Thanks.

[jam, 2013-11-25 16:35:51]

rubberstamp lgtm with nits

https://codereview.chromium.org/79193003/diff/170001/content/browser/renderer...
File content/browser/renderer_host/render_process_host_impl.cc (right):

https://codereview.chromium.org/79193003/diff/170001/content/browser/renderer...
content/browser/renderer_host/render_process_host_impl.cc:973: #if
defined(OS_ANDROID) && defined(ARCH_CPU_X86)
nit: follow the local style and put ifdef'd sections at the bottom of the list

https://codereview.chromium.org/79193003/diff/170001/content/public/common/co...
File content/public/common/content_switches.cc (right):

https://codereview.chromium.org/79193003/diff/170001/content/public/common/co...
content/public/common/content_switches.cc:315: #if defined(OS_ANDROID) &&
defined(ARCH_CPU_X86)
ditto

https://codereview.chromium.org/79193003/diff/170001/content/public/common/co...
File content/public/common/content_switches.h (right):

https://codereview.chromium.org/79193003/diff/170001/content/public/common/co...
content/public/common/content_switches.h:107: CONTENT_EXPORT extern const char
kEnableWebAudio[];
nit: follow the style in this file by putting ifdef sections at bottom (also
note this file is sorted)

[Raymond Toy (Google), 2013-12-05 23:52:45]

On 2013/11/25 16:35:51, jam wrote:
> rubberstamp lgtm with nits
> 
>
https://codereview.chromium.org/79193003/diff/170001/content/browser/renderer...
> File content/browser/renderer_host/render_process_host_impl.cc (right):
> 
>
https://codereview.chromium.org/79193003/diff/170001/content/browser/renderer...
> content/browser/renderer_host/render_process_host_impl.cc:973: #if
> defined(OS_ANDROID) && defined(ARCH_CPU_X86)
> nit: follow the local style and put ifdef'd sections at the bottom of the list
> 
>
https://codereview.chromium.org/79193003/diff/170001/content/public/common/co...
> File content/public/common/content_switches.cc (right):
> 
>
https://codereview.chromium.org/79193003/diff/170001/content/public/common/co...
> content/public/common/content_switches.cc:315: #if defined(OS_ANDROID) &&
> defined(ARCH_CPU_X86)
> ditto
> 
>
https://codereview.chromium.org/79193003/diff/170001/content/public/common/co...
> File content/public/common/content_switches.h (right):
> 
>
https://codereview.chromium.org/79193003/diff/170001/content/public/common/co...
> content/public/common/content_switches.h:107: CONTENT_EXPORT extern const char
> kEnableWebAudio[];
> nit: follow the style in this file by putting ifdef sections at bottom (also
> note this file is sorted)

Thanks for the review.  I've moved everything as you've suggested and tried to
make it alphabetical ordering where possible.

There was a small change in patch #5.  --disable-webaudio still needs to be
supported on all platforms where WebAudio is enabled by default without an
about:flags entry.

[commit-bot: I haz the power, 2013-12-06 06:26:44]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rtoy@google.com/79193003/280001

[commit-bot: I haz the power, 2013-12-06 07:05:45]

Retried try job too often on android_aosp for step(s) compile
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=android_ao...

[commit-bot: I haz the power, 2013-12-06 19:09:41]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rtoy@google.com/79193003/300001

[commit-bot: I haz the power, 2013-12-06 23:28:22]

Retried try job too often on android_aosp for step(s) compile
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=android_ao...

[commit-bot: I haz the power, 2013-12-09 17:30:37]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rtoy@google.com/79193003/300001

[commit-bot: I haz the power, 2013-12-09 18:13:17]

Change committed as 239518