Add a CONNECT_REQUESTED state to Network ConnectionState

Add a CONNECT_REQUESTED state to Network ConnectionState. 
When a connection request is made, Chrome now sets the state to CONNECT_REQUESTED and ignores "Idle" state updates while in that state. 
This informs the UI to show "connecting" icons / text until the connection attempt succeeds or fails. 
Also: Don't update the network icon while scanning. 
Also: includes a bunch of logging changes for improved debugging. 

This alos fixes the mock expectations so that browser_tests should pass.

Original CL: https://chromiumcodereview.appspot.com/10554013

BUG=125121
TEST=See issue, test connecting between networks, UI should behave correctly. 
For chrome/browser/chromeos/gdata:
TBR=gspencer@chromium.org, tbarzic@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=143072