Revert 93106 - Reparenting of RendererGLContexts supports going from no parent to having a parent.

RendererGLContext::SetParent is a no-op if the parent did not change to avoid a redundant sync IPC.

Added SetParentContext to WebGraphicsContext3DCommandBufferImpl. WebKit change to follow.
Review URL: http://codereview.chromium.org/7237009

TBR=apatrick@chromium.org
Review URL: http://codereview.chromium.org/7475001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@93244 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 20 insertions, 13 deletions

diff --git a/content/renderer/gpu/renderer_gl_context.cc b/content/renderer/gpu/renderer_gl_context.cc
index 4937a46..bf2d100 100644
--- a/content/renderer/gpu/renderer_gl_context.cc
+++ b/content/renderer/gpu/renderer_gl_context.cc
@@ -224,9 +224,6 @@ RendererGLContext* RendererGLContext::CreateOffscreenContext(
 }
 
 bool RendererGLContext::SetParent(RendererGLContext* new_parent) {
-  if (parent_.get() == new_parent)
-    return true;
-
   // Allocate a texture ID with respect to the parent and change the parent.
   uint32 new_parent_texture_id = 0;
   if (command_buffer_) {
diff --git a/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc b/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc
index 04bfe9d..2d825b9 100644
--- a/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc
+++ b/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc
@@ -106,6 +106,7 @@ bool WebGraphicsContext3DCommandBufferImpl::initialize(
   if (web_view && web_view->mainFrame())
     active_url = GURL(web_view->mainFrame()->document().url());
 
+  RendererGLContext* parent_context = NULL;
   if (render_directly_to_web_view) {
     RenderView* renderview = RenderView::FromWebView(web_view);
     if (!renderview)
@@ -124,6 +125,22 @@ bool WebGraphicsContext3DCommandBufferImpl::initialize(
               &WebGraphicsContext3DCommandBufferImpl::OnSwapBuffersComplete));
     }
   } else {
+    bool compositing_enabled = !CommandLine::ForCurrentProcess()->HasSwitch(
+        switches::kDisableAcceleratedCompositing);
+    // If GPU compositing is enabled we need to create a GL context that shares
+    // resources with the compositor's context.
+    if (compositing_enabled) {
+      // Asking for the WebGraphicsContext3D on the WebView will force one to
+      // be created if it doesn't already exist. When the compositor is created
+      // for the view it will use the same context.
+      WebKit::WebGraphicsContext3D* view_context =
+          web_view->graphicsContext3D();
+      if (view_context) {
+        WebGraphicsContext3DCommandBufferImpl* context_impl =
+            static_cast<WebGraphicsContext3DCommandBufferImpl*>(view_context);
+        parent_context = context_impl->context_;
+      }
+    }
     context_ = RendererGLContext::CreateOffscreenContext(
         host,
         gfx::Size(1, 1),
@@ -135,6 +152,9 @@ bool WebGraphicsContext3DCommandBufferImpl::initialize(
   if (!context_)
     return false;
 
+  if (!context_->SetParent(parent_context))
+    return false;
+
   gl_ = context_->GetImplementation();
   context_->SetContextLostCallback(
       NewCallback(this,
@@ -182,14 +202,6 @@ bool WebGraphicsContext3DCommandBufferImpl::isGLES2Compliant() {
   return true;
 }
 
-bool WebGraphicsContext3DCommandBufferImpl::setParentContext(
-    WebGraphicsContext3D* parent_context) {
-  WebGraphicsContext3DCommandBufferImpl* parent_context_impl =
-      static_cast<WebGraphicsContext3DCommandBufferImpl*>(parent_context);
-  return context_->SetParent(
-      parent_context_impl ? parent_context_impl->context() : NULL);
-}
-
 WebGLId WebGraphicsContext3DCommandBufferImpl::getPlatformTextureId() {
   DCHECK(context_);
   return context_->GetParentTextureId();
diff --git a/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h b/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h
index e291c82..5411502 100644
--- a/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h
+++ b/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h
@@ -64,8 +64,6 @@ class WebGraphicsContext3DCommandBufferImpl
 
   virtual bool isGLES2Compliant();
 
-  virtual bool setParentContext(WebGraphicsContext3D* parent_context);
-
   virtual void reshape(int width, int height);
 
   virtual bool readBackFramebuffer(unsigned char* pixels, size_t buffer_size);