Add VaapiVideoEncodeAccelerator for HW-accelerated video encode.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index efe852b1a15f19743b1d06e6bdb6c29209d22558..8bd4a919f6cf1291bf24db62f2a0fd46f3826633 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -1249,6 +1249,9 @@ void RenderProcessHostImpl::PropagateBrowserCommandLineToRenderer(
     switches::kDisableDirectWrite,
     switches::kEnableHighResolutionTime,
 #endif
+#if defined(OS_CHROMEOS)
+    switches::kEnableVaapiAcceleratedVideoEncode,
+#endif

[piman, 2014/06/20 17:10:22]

I don't see where this is used in the renderer.

[Pawel Osciak, 2014/06/20 22:28:11]

Yeah, this is a bit convoluted. We need a way to be able to tell which
codecs/profiles are supported by a hw encoder from the renderer on request from
libjingle, before we make a decision to instantiate the codec in GPU process.

The method used to retrieve the list of supported codecs is currently a hack, a
hardcoded in each accelerator VEA::GetSupportedProfiles, which is actually a
static method in HW accelerators executed in renderer from
RTCVideoEncoderFactory
(https://code.google.com/p/chromium/codesearch#chromium/src/content/renderer/m...)
and then used to decide if we would be able to fulfill webrtc's request for a HW
codec that would support given profile
(https://code.google.com/p/chromium/codesearch#chromium/src/content/renderer/m...).

We are working on a proper solution for this (crbug.com/350197) which will add
codec feature autodetection, this is temporary.
Until that is ready however, the flag is checked in GetSupportedProfiles in HW
encoders when called from renderer and is used to decide what can be added to
the list of supported profiles. In
VaapiVideoEncodeAccelerator::GetSupportedProfiles, the flag gates everything, so
no profiles will be added to the list if it's not on. Not having any profiles on
the list will result in that we'll not match any requested codecs in
RTCVideoEncoderFactory and VaapiVideoEncodeAccelerator will never be
instantiated.

   };
   renderer_cmd->CopySwitchesFrom(browser_cmd, kSwitchNames,
                                  arraysize(kSwitchNames));