GraphDealer: resolve race condition
GraphDealer: resolve race condition

Resolve race condition between loading profiles and extracts with a
new `onProfileData` promise. Pull out a new private `loadProfileData`
function to handle mutating shared state.

refs #742 (.25)

NProfileAnalysisComputationalTool/npact,victor-lin/npact,victor-lin/npact,victor-lin/npact,NProfileAnalysisComputationalTool/npact,NProfileAnalysisComputationalTool/npact,victor-lin/npact,victor-lin/npact,NProfileAnalysisComputationalTool/npact,NProfileAnalysisComputationalTool/npact