Bug 476405

SUMMARY
When selecting a blend mode for a layer in the layer docker, the focus remains on the blendmode selection dropdown until the user interacts with the canvas. This means that if the user has bound keyboard shortcuts to alphabet keys and uses them before interacting with the canvas, they will inadvertently change the blending mode of the layer they are working on.

For example, I have "brush size" bound to "s". This means that almost every time I select a new layer blend mode, I end up setting the layer to "saturation" since the first thing I do when I start painting on a layer is to check my brush size.

STEPS TO REPRODUCE
1. set a layer's blend mode to any blend mode you wish
2. move cursor over the canvas
3. press a shortcut key like 's'.

OBSERVED RESULT
The layer blending mode changes 

EXPECTED RESULT
The blending mode should not change



ADDITIONAL INFORMATION
Ideally, I think focus should shift away from the blendmode selection box as soon as the cursor is over the canvas. If this can't be done reliably and quickly (IIRC there is some delay for focus shifting), I at least would prefer not having the blendmode shortcuts at all, so maybe an option for that.