Prepare WebGL contexts for resource sharing with the compositor context.

content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.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.
 
 #if defined(ENABLE_GPU)
 
 #include "content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h"
 
 #include "gpu/GLES2/gl2.h"
 #ifndef GL_GLEXT_PROTOTYPES
@@ skipping 48 matching lines @@
 
 WebGraphicsContext3DCommandBufferImpl::
     ~WebGraphicsContext3DCommandBufferImpl() {
   {
     base::AutoLock lock(g_all_shared_contexts_lock.Get());
     g_all_shared_contexts.Pointer()->erase(this);
   }
   delete context_;
 }
 
-// This string should only be passed for WebGL contexts. Nothing ELSE!!!
-// Compositor contexts, Canvas2D contexts, Pepper Contexts, nor any other use of
-// a context should not pass this string.
-static const char* kWebGLPreferredGLExtensions =
-    "GL_OES_packed_depth_stencil "
-    "GL_OES_depth24 "
-    "GL_CHROMIUM_webglsl";
-
 bool WebGraphicsContext3DCommandBufferImpl::initialize(
     WebGraphicsContext3D::Attributes attributes,
     WebKit::WebView* web_view,
     bool render_directly_to_web_view) {
   DCHECK(!context_);
   TRACE_EVENT0("gpu", "WebGfxCtx3DCmdBfrImpl::initialize");
   RenderThread* render_thread = RenderThread::current();
   if (!render_thread)
     return false;
   host_ = render_thread->EstablishGpuChannelSync(
@@ skipping 49 matching lines @@
     RendererGLContext::ALPHA_SIZE, alpha_size,
     RendererGLContext::DEPTH_SIZE, depth_size,
     RendererGLContext::STENCIL_SIZE, stencil_size,
     RendererGLContext::SAMPLES, samples,
     RendererGLContext::SAMPLE_BUFFERS, sample_buffers,
     RendererGLContext::SHARE_RESOURCES, attributes_.shareResources ? 1 : 0,
     RendererGLContext::BIND_GENERATES_RESOURCES, 0,
     RendererGLContext::NONE,
   };
 
-  const char* preferred_extensions = attributes_.noExtensions ?
-      kWebGLPreferredGLExtensions : "*";
+  const char* preferred_extensions = "*";
 
   // We need to lock g_all_shared_contexts until after RendererGLContext::Create
   // to ensure that the context we picked for our share group isn't deleted.
   // (There's also a lock in our destructor.)
   {
     base::AutoLock lock(g_all_shared_contexts_lock.Get());
     RendererGLContext* share_group = NULL;
     if (attributes_.shareResources) {
       share_group = g_all_shared_contexts.Pointer()->empty() ?
           NULL : (*g_all_shared_contexts.Pointer()->begin())->context_;
@@ skipping 15 matching lines @@
           preferred_extensions,
           attribs,
           active_url_);
     }
   }
 
   if (!context_)
     return false;
 
   gl_ = context_->GetImplementation();
+
+  // TODO(twiz):  This code is too fragile in that it assumes that only WebGL
+  // contexts will request noExtensions.
+  if (gl_ && attributes_.noExtensions)
+    gl_->EnableFeatureCHROMIUM("webgl_enable_glsl_webgl_validation");
+
   context_->SetContextLostCallback(
       NewCallback(this,
                   &WebGraphicsContext3DCommandBufferImpl::OnContextLost));
 
   // TODO(gman): Remove this.
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
   if (command_line.HasSwitch(switches::kDisableGLSLTranslator)) {
     context_->DisableShaderTranslation();
   }
 
@@ skipping 900 matching lines @@
   }
 #ifndef WTF_USE_THREADED_COMPOSITING
   RenderView* renderview =
       web_view_ ? RenderView::FromWebView(web_view_) : NULL;
   if (renderview)
     renderview->OnViewContextSwapBuffersAborted();
 #endif
 }
 
 #endif  // defined(ENABLE_GPU)