Route IPC through browser when creating a viewable command buffer.

The communications path for creating a viewable command buffer used to be directly from the renderer (gpu_channel.cc) to the gpu process (gpu_channel.cc).  This patch makes the browser an intermediary:

- renderer (gpu_channel.cc) makes a synchronous request to the browser (picked up in renderer_message_filter.cc and forwarded to gpu_process_host.cc)

- browser (gpu_process_host.cc) makes an asynchronous request to the gpu process (picked up in gpu_thread.cc and forwarded to gpu_channel.cc) for the command buffer

- gpu process (gpu_thread.cc) sends an ACK with the route_id for the command buffer back to the browser (gpu_process_host.cc)

- browser (gpu_process_host.cc) sends a delayed reply back to the renderer
(gpu_channel_host.cc), which had blocked

There are several motivations for this patch:

- creating an onscreen command buffer requires a window to draw into (which is acquired/locked in the browser); by routing through the browser, we can acquire the get the window beforehand (thereby preventing a deadlock in some other work that I'm doing)

- we can eliminate several separate synchronous IPC messages for obtaining and releasing the window associated with drawing (I've tried to unify the different code paths for Linux, Windows, and Mac)

- in the future, we can have the browser allocate SHM for the command buffer and transfer buffers, allowing us to sandbox the gpu process

BUG=none
TEST=by hand on all 3 platforms, trybots

Review URL: http://codereview.chromium.org/6343006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@72798 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 1 insertions, 25 deletions

diff --git a/chrome/renderer/webgraphicscontext3d_command_buffer_impl.cc b/chrome/renderer/webgraphicscontext3d_command_buffer_impl.cc
index 1d8e5d6..0e97b94 100644
--- a/chrome/renderer/webgraphicscontext3d_command_buffer_impl.cc
+++ b/chrome/renderer/webgraphicscontext3d_command_buffer_impl.cc
@@ -27,9 +27,6 @@
 WebGraphicsContext3DCommandBufferImpl::WebGraphicsContext3DCommandBufferImpl()
     : context_(NULL),
       web_view_(NULL),
-#if defined(OS_MACOSX)
-      plugin_handle_(NULL),
-#endif  // defined(OS_MACOSX)
       cached_width_(0),
       cached_height_(0),
       bound_fbo_(0) {
@@ -37,19 +34,6 @@ WebGraphicsContext3DCommandBufferImpl::WebGraphicsContext3DCommandBufferImpl()
 
 WebGraphicsContext3DCommandBufferImpl::
     ~WebGraphicsContext3DCommandBufferImpl() {
-#if defined(OS_MACOSX)
-  if (web_view_) {
-    DCHECK(plugin_handle_ != gfx::kNullPluginWindow);
-    RenderView* renderview = RenderView::FromWebView(web_view_);
-    // The RenderView might already have been freed, but in its
-    // destructor it destroys all fake plugin window handles it
-    // allocated.
-    if (renderview) {
-      renderview->DestroyFakePluginWindowHandle(plugin_handle_);
-    }
-    plugin_handle_ = gfx::kNullPluginWindow;
-  }
-#endif
   if (context_) {
     ggl::DestroyContext(context_);
   }
@@ -101,18 +85,10 @@ bool WebGraphicsContext3DCommandBufferImpl::initialize(
     RenderView* renderview = RenderView::FromWebView(web_view);
     if (!renderview)
       return false;
-    gfx::NativeViewId view_id;
-#if !defined(OS_MACOSX)
-    view_id = renderview->host_window();
-#else
-    plugin_handle_ = renderview->AllocateFakePluginWindowHandle(
-        /*opaque=*/true, /*root=*/true);
-    view_id = static_cast<gfx::NativeViewId>(plugin_handle_);
-#endif
+
     web_view_ = web_view;
     context_ = ggl::CreateViewContext(
         host,
-        view_id,
         renderview->routing_id(),
         kWebGraphicsContext3DPerferredGLExtensions,
         attribs);