Reland "GPU: Reduce MakeCurrent calls to fix Orange San Diego""

This patch now also always calls MakeVirtuallyCurrent during initialize and
MakeCurrent, such that the next context will always restore. The context state is
restored only if the API has changed or the virtually current context has changed,
so we should never skip calling MakeVirtuallyCurrent.

BUG=241188

Review URL: https://chromiumcodereview.appspot.com/15841002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202561 0039d316-1c4b-4281-b951-d872f2087c98

gpu/command_buffer/service/gl_context_virtual.cc

@@ -30,12 +30,20 @@ bool GLContextVirtual::Initialize(
 
   display_ = static_cast<gfx::Display*>(compatible_surface->GetDisplay());
 
-  if (!shared_context_->MakeCurrent(compatible_surface))
-    return false;
+  // Virtual contexts obviously can't make a context that is compatible
+  // with the surface (the context already exists), but we do need to
+  // make a context current for SetupForVirtualization() below.
+  if (!IsCurrent(compatible_surface)) {
+    if (!shared_context_->MakeCurrent(compatible_surface)) {
+      // This is likely an error. The real context should be made as
+      // compatible with all required surfaces when it was created.
+      LOG(ERROR) << "Failed MakeCurrent(compatible_surface)";
+      return false;
+    }
+  }
 
   shared_context_->SetupForVirtualization();
-
-  shared_context_->ReleaseCurrent(compatible_surface);
+  shared_context_->MakeVirtuallyCurrent(this, compatible_surface);
   return true;
 }
 
@@ -46,9 +54,12 @@ void GLContextVirtual::Destroy() {
 }
 
 bool GLContextVirtual::MakeCurrent(gfx::GLSurface* surface) {
-  if (decoder_.get() && decoder_->initialized())
+  // TODO(epenner): We should avoid bypassing MakeVirtuallyCurrent() below
+  // (return false or DCHECK when !decoder). To do this we must reorder
+  // tear-down in GpuCommandBufferStub::Destroy().
+  if (decoder_.get())
     shared_context_->MakeVirtuallyCurrent(this, surface);
-  else
+  else if (!IsCurrent(surface))
     shared_context_->MakeCurrent(surface);
   return true;
 }
@@ -59,18 +70,14 @@ void GLContextVirtual::ReleaseCurrent(gfx::GLSurface* surface) {
 }
 
 bool GLContextVirtual::IsCurrent(gfx::GLSurface* surface) {
-  bool context_current = shared_context_->IsCurrent(NULL);
-  if (!context_current)
-    return false;
-
-  if (!surface)
-    return true;
-
-  gfx::GLSurface* current_surface = gfx::GLSurface::GetCurrent();
-  return surface->GetBackingFrameBufferObject() ||
-      surface->IsOffscreen() ||
-      (current_surface &&
-       current_surface->GetHandle() == surface->GetHandle());
+  // If it's a real surface it needs to be current.
+  if (surface &&
+      !surface->GetBackingFrameBufferObject() &&
+      !surface->IsOffscreen())
+    return shared_context_->IsCurrent(surface);
+
+  // Otherwise, only insure the context itself is current.
+  return shared_context_->IsCurrent(NULL);
 }
 
 void* GLContextVirtual::GetHandle() {

gpu/command_buffer/service/gl_state_restorer_impl.cc

@@ -16,6 +16,11 @@ GLStateRestorerImpl::GLStateRestorerImpl(
 GLStateRestorerImpl::~GLStateRestorerImpl() {
 }
 
+bool GLStateRestorerImpl::IsInitialized() {
+  DCHECK(decoder_.get());
+  return decoder_->initialized();
+}
+
 void GLStateRestorerImpl::RestoreState() {
   DCHECK(decoder_.get());
   decoder_->RestoreState();

gpu/command_buffer/service/gl_state_restorer_impl.h

@@ -23,6 +23,7 @@ class GPU_EXPORT GLStateRestorerImpl : public gfx::GLStateRestorer {
    explicit GLStateRestorerImpl(base::WeakPtr<gles2::GLES2Decoder> decoder);
    virtual ~GLStateRestorerImpl();
 
+   virtual bool IsInitialized() OVERRIDE;
    virtual void RestoreState() OVERRIDE;
    virtual void RestoreAllTextureUnitBindings() OVERRIDE;
    virtual void RestoreFramebufferBindings() OVERRIDE;

ui/gl/gl_gl_api_implementation.cc

@@ -285,7 +285,8 @@ bool VirtualGLApi::MakeCurrent(GLContext* virtual_context, GLSurface* surface) {
     // needed for individual GL calls.
     GLApi* temp = GetCurrentGLApi();
     SetGLToRealGLApi();
-    virtual_context->GetGLStateRestorer()->RestoreState();
+    if (virtual_context->GetGLStateRestorer()->IsInitialized())
+      virtual_context->GetGLStateRestorer()->RestoreState();
     SetGLApi(temp);
   }
   SetGLApi(this);

ui/gl/gl_state_restorer.h

@@ -17,6 +17,7 @@ class GL_EXPORT GLStateRestorer {
   GLStateRestorer();
   virtual ~GLStateRestorer();
 
+  virtual bool IsInitialized() = 0;
   virtual void RestoreState() = 0;
   virtual void RestoreAllTextureUnitBindings() = 0;
   virtual void RestoreFramebufferBindings() = 0;