During virtual context switches only restore texture units that have changed from the previous cont…

ui/gl/gl_gl_api_implementation.cc

Index: ui/gl/gl_gl_api_implementation.cc
diff --git a/ui/gl/gl_gl_api_implementation.cc b/ui/gl/gl_gl_api_implementation.cc
index eade3cedaf5e6df54041372b964335aa7937edca..0123a95437eae3d9828d8b523b317a8dd7b8c4e1 100644
--- a/ui/gl/gl_gl_api_implementation.cc
+++ b/ui/gl/gl_gl_api_implementation.cc
@@ -305,17 +305,17 @@ bool VirtualGLApi::MakeCurrent(GLContext* virtual_context, GLSurface* surface) {
     // new context.
     DCHECK_EQ(glGetErrorFn(), static_cast<GLenum>(GL_NO_ERROR));
 
-    current_context_ = virtual_context;
     // Set all state that is different from the real state
-    // NOTE: !!! This is a temporary implementation that just restores all
-    // state to let us test that it works.
-    // TODO: ASAP, change this to something that only restores the state
-    // needed for individual GL calls.
     GLApi* temp = GetCurrentGLApi();
     SetGLToRealGLApi();
-    if (virtual_context->GetGLStateRestorer()->IsInitialized())
-      virtual_context->GetGLStateRestorer()->RestoreState();
+    if (virtual_context->GetGLStateRestorer()->IsInitialized()) {
+      virtual_context->GetGLStateRestorer()->RestoreState(
+          (current_context_)

[Sami, 2013/12/18 16:04:07]

It might be worth checking how often we go from MakeCurrent(NULL) =>
MakeCurrent(some_context) since that would defeat this optimization. I'm not
sure if that ever happens with virtual contexts though.

[kaanb, 2013/12/18 17:24:55]

I see MakeCurrent(NULL) -> MakeCurrent(some_context) transition a few times when
I first open a tab but not afterwards. 

+              ? current_context_->GetGLStateRestorer()->GetContextState()
+              : NULL);
+    }
     SetGLApi(temp);
+    current_context_ = virtual_context;
   }
   SetGLApi(this);