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

8 files changed, 61 insertions, 45 deletions

diff --git a/content/renderer/gpu/renderer_gl_context.cc b/content/renderer/gpu/renderer_gl_context.cc
index bf2d100..4937a46 100644
--- a/content/renderer/gpu/renderer_gl_context.cc
+++ b/content/renderer/gpu/renderer_gl_context.cc
@@ -224,6 +224,9 @@ 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 ffb997f..57cac38 100644
--- a/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc
+++ b/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc
@@ -106,7 +106,6 @@ 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)
@@ -125,22 +124,6 @@ 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),
@@ -152,9 +135,6 @@ bool WebGraphicsContext3DCommandBufferImpl::initialize(
   if (!context_)
     return false;
 
-  if (!context_->SetParent(parent_context))
-    return false;
-
   gl_ = context_->GetImplementation();
   context_->SetContextLostCallback(
       NewCallback(this,
@@ -202,6 +182,14 @@ 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 5411502..e291c82 100644
--- a/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h
+++ b/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h
@@ -64,6 +64,8 @@ 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);
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(),
diff --git a/webkit/gpu/webgraphicscontext3d_in_process_command_buffer_impl.cc b/webkit/gpu/webgraphicscontext3d_in_process_command_buffer_impl.cc
index 36858fb..f633323 100644
--- a/webkit/gpu/webgraphicscontext3d_in_process_command_buffer_impl.cc
+++ b/webkit/gpu/webgraphicscontext3d_in_process_command_buffer_impl.cc
@@ -881,6 +881,11 @@ bool WebGraphicsContext3DInProcessCommandBufferImpl::isGLES2Compliant() {
   return true;
 }
 
+bool WebGraphicsContext3DInProcessCommandBufferImpl::setParentContext(
+    WebGraphicsContext3D* parent_context) {
+  return false;
+}
+
 WebGLId WebGraphicsContext3DInProcessCommandBufferImpl::getPlatformTextureId() {
   DCHECK(context_);
   return context_->GetParentTextureId();
diff --git a/webkit/gpu/webgraphicscontext3d_in_process_command_buffer_impl.h b/webkit/gpu/webgraphicscontext3d_in_process_command_buffer_impl.h
index 5e2df99..ce6ce46 100644
--- a/webkit/gpu/webgraphicscontext3d_in_process_command_buffer_impl.h
+++ b/webkit/gpu/webgraphicscontext3d_in_process_command_buffer_impl.h
@@ -65,6 +65,8 @@ class WebGraphicsContext3DInProcessCommandBufferImpl
 
   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);
diff --git a/webkit/gpu/webgraphicscontext3d_in_process_impl.cc b/webkit/gpu/webgraphicscontext3d_in_process_impl.cc
index e7d5757..a729099 100644
--- a/webkit/gpu/webgraphicscontext3d_in_process_impl.cc
+++ b/webkit/gpu/webgraphicscontext3d_in_process_impl.cc
@@ -298,6 +298,11 @@ bool WebGraphicsContext3DInProcessImpl::isGLES2Compliant() {
   return is_gles2_;
 }
 
+bool WebGraphicsContext3DInProcessImpl::setParentContext(
+    WebGraphicsContext3D* parent_context) {
+  return false;
+}
+
 WebGLId WebGraphicsContext3DInProcessImpl::getPlatformTextureId() {
   return texture_;
 }
diff --git a/webkit/gpu/webgraphicscontext3d_in_process_impl.h b/webkit/gpu/webgraphicscontext3d_in_process_impl.h
index aafff28..05bc06d 100644
--- a/webkit/gpu/webgraphicscontext3d_in_process_impl.h
+++ b/webkit/gpu/webgraphicscontext3d_in_process_impl.h
@@ -65,6 +65,8 @@ class WebGraphicsContext3DInProcessImpl : public WebGraphicsContext3D {
 
   virtual bool isGLES2Compliant();
 
+  virtual bool setParentContext(WebGraphicsContext3D* parent_context);
+
   virtual void reshape(int width, int height);
 
   virtual bool readBackFramebuffer(unsigned char* pixels, size_t bufferSize);