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

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@93106 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 34 insertions, 25 deletions

diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index d5bd745..1dcfd51 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -470,6 +470,7 @@ class GLES2DecoderImpl : public base::SupportsWeakPtr<GLES2DecoderImpl>,
                          uint32 parent_texture_id);
   virtual void ResizeOffscreenFrameBuffer(const gfx::Size& size);
   virtual bool UpdateOffscreenFrameBufferSize();
+  void UpdateParentTextureInfo();
   virtual bool MakeCurrent();
   virtual GLES2Util* GetGLES2Util() { return &util_; }
   virtual gfx::GLContext* GetGLContext() { return context_.get(); }
@@ -2273,21 +2274,36 @@ bool GLES2DecoderImpl::UpdateOffscreenFrameBufferSize() {
     RestoreClearState();
   }
 
-  if (parent_ || IsOffscreenBufferMultisampled()) {
-    DCHECK(offscreen_saved_color_format_);
-    offscreen_saved_color_texture_->AllocateStorage(
-        pending_offscreen_size_, offscreen_saved_color_format_);
+  // Allocate the offscreen saved color texture.
+  DCHECK(offscreen_saved_color_format_);
+  offscreen_saved_color_texture_->AllocateStorage(
+      pending_offscreen_size_, offscreen_saved_color_format_);
 
-    offscreen_saved_frame_buffer_->AttachRenderTexture(
-        offscreen_saved_color_texture_.get());
-    if (offscreen_saved_frame_buffer_->CheckStatus() !=
-        GL_FRAMEBUFFER_COMPLETE) {
-      LOG(ERROR) << "GLES2DecoderImpl::UpdateOffscreenFrameBufferSize failed "
-                 << "because offscreen saved FBO was incomplete.";
-      return false;
-    }
+  offscreen_saved_frame_buffer_->AttachRenderTexture(
+      offscreen_saved_color_texture_.get());
+  if (offscreen_saved_frame_buffer_->CheckStatus() !=
+      GL_FRAMEBUFFER_COMPLETE) {
+    LOG(ERROR) << "GLES2DecoderImpl::UpdateOffscreenFrameBufferSize failed "
+               << "because offscreen saved FBO was incomplete.";
+    return false;
+  }
+
+  // Clear the offscreen color texture.
+  {
+    ScopedFrameBufferBinder binder(this, offscreen_saved_frame_buffer_->id());
+    glClearColor(0, 0, 0, 0);
+    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
+    glDisable(GL_SCISSOR_TEST);
+    glClear(GL_COLOR_BUFFER_BIT);
+    RestoreClearState();
   }
 
+  UpdateParentTextureInfo();
+
+  return true;
+}
+
+void GLES2DecoderImpl::UpdateParentTextureInfo() {
   if (parent_) {
     // Update the info about the offscreen saved color texture in the parent.
     // The reference to the parent is a weak pointer and will become null if the
@@ -2331,19 +2347,7 @@ bool GLES2DecoderImpl::UpdateOffscreenFrameBufferSize() {
         info,
         GL_TEXTURE_WRAP_T,
         GL_CLAMP_TO_EDGE);
-
-    // Clear the offscreen color texture.
-    {
-      ScopedFrameBufferBinder binder(this, offscreen_saved_frame_buffer_->id());
-      glClearColor(0, 0, 0, 0);
-      glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
-      glDisable(GL_SCISSOR_TEST);
-      glClear(GL_COLOR_BUFFER_BIT);
-      RestoreClearState();
-    }
   }
-
-  return true;
 }
 
 void GLES2DecoderImpl::SetResizeCallback(Callback1<gfx::Size>::Type* callback) {
@@ -2441,6 +2445,9 @@ void GLES2DecoderImpl::Destroy() {
 
 bool GLES2DecoderImpl::SetParent(GLES2Decoder* new_parent,
                                  uint32 new_parent_texture_id) {
+  if (!offscreen_saved_color_texture_.get())
+    return false;
+
   // Remove the saved frame buffer mapping from the parent decoder. The
   // parent pointer is a weak pointer so it will be null if the parent has
   // already been destroyed.
@@ -2473,6 +2480,8 @@ bool GLES2DecoderImpl::SetParent(GLES2Decoder* new_parent,
     new_parent_impl->texture_manager()->SetInfoTarget(info, GL_TEXTURE_2D);
 
     parent_ = new_parent_impl->AsWeakPtr();
+
+    UpdateParentTextureInfo();
   } else {
     parent_.reset();
   }
@@ -6485,7 +6494,7 @@ error::Error GLES2DecoderImpl::HandleSwapBuffers(
       ScopedFrameBufferBinder binder(this,
                                      offscreen_target_frame_buffer_->id());
 
-      if (parent_) {
+      if (surface_->IsOffscreen()) {
         // Copy the target frame buffer to the saved offscreen texture.
         offscreen_saved_color_texture_->Copy(
             offscreen_saved_color_texture_->size(),