Use 3D graphics context shareResources flag to decide whether a context should share resources.

content/renderer/render_widget_fullscreen_pepper.cc

 // Copyright (c) 2011 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 "content/renderer/render_widget_fullscreen_pepper.h"
 
 #include "base/message_loop.h"
 #include "content/common/view_messages.h"
 #include "content/renderer/gpu/gpu_channel_host.h"
 #include "content/renderer/pepper_platform_context_3d_impl.h"
@@ skipping 330 matching lines @@
   GpuChannelHost* host = render_thread->EstablishGpuChannelSync(
     content::CAUSE_FOR_GPU_LAUNCH_RENDERWIDGETFULLSCREENPEPPER_CREATECONTEXT);
   if (!host)
     return;
   const int32 attribs[] = {
     RendererGLContext::ALPHA_SIZE, 8,
     RendererGLContext::DEPTH_SIZE, 0,
     RendererGLContext::STENCIL_SIZE, 0,
     RendererGLContext::SAMPLES, 0,
     RendererGLContext::SAMPLE_BUFFERS, 0,
+    RendererGLContext::SHARE_RESOURCES, 0,
+    RendererGLContext::BIND_GENERATES_RESOURCES, 1,

[piman, 2011/08/26 23:18:57]

I think this was false before (the default), do we want to set it to 0 ?
We don't rely on the behavior either way, so whatever is most efficient is good.

[apatrick_chromium, 2011/08/26 23:40:01]

False referred to whether resource sharing was enabled. It is still false. See
SHARE_RESOURCES above. BIND_GENERATES_RESOURCES is a new option and is true for
Pepper, and corresponds to regular GLES2 semantics, which I think is what you
want.

[piman, 2011/08/27 00:40:42]

This is for the full-screen "compositor" (which scales and draws the Pepper
content which has its own separate context). So it's actually ok to not have the
GLES2 semantics here, if it's more efficient. But it's not necessarily
important.

     RendererGLContext::NONE,
   };
   context_ = RendererGLContext::CreateViewContext(
       host,
       routing_id(),
-      false,
       NULL,
       "GL_OES_packed_depth_stencil GL_OES_depth24",
       attribs,
       active_url_);
   if (!context_)
     return;
 
   if (!InitContext()) {
     DestroyContext(context_, program_, buffer_);
     context_ = NULL;
@@ skipping 128 matching lines @@
   context_ = NULL;
   program_ = 0;
   buffer_ = 0;
   OnSwapBuffersAborted();
   CheckCompositing();
 }
 
 void RenderWidgetFullscreenPepper::OnSwapBuffersCompleteByRendererGLContext() {
   OnSwapBuffersComplete();
 }