gpu: Add GpuFence framework.

gpu/gles2_conform_support/egl/context.cc

Index: gpu/gles2_conform_support/egl/context.cc
diff --git a/gpu/gles2_conform_support/egl/context.cc b/gpu/gles2_conform_support/egl/context.cc
index 2d870e7dc2dca6c0317e68995195ee306d4083e0..48e2ea9a7545cfb4ee9ea6dff7d46266c1c0d4b7 100644
--- a/gpu/gles2_conform_support/egl/context.cc
+++ b/gpu/gles2_conform_support/egl/context.cc
@@ -230,6 +230,15 @@ bool Context::CanWaitUnverifiedSyncToken(const gpu::SyncToken* sync_token) {
   return false;
 }
 
+int32_t Context::CreateFence(ClientFence fence) {
+  NOTIMPLEMENTED();
+  return -1;
+}
+
+void Context::DestroyFence(int32_t id) {
+  NOTIMPLEMENTED();
+}
+
 void Context::ApplyCurrentContext(gl::GLSurface* current_surface) {
   DCHECK(HasService());
   // The current_surface will be the same as