tests: use progress helper

With this commit, the only in-tree caller of ui.progress() is
scmutil.progress(). That means that we could deprecate it. It also
means that we can considering inlining it in scmutil.progress.

Differential Revision: https://phab.mercurial-scm.org/D3812

tests/test-progress.t

@@ -33,20 +33,22 b''
   >         nested = True
   >     loops = abs(loops)
   > 
+  >     progress = ui.makeprogress(topiclabel, unit='loopnum', total=total)
+  >     other = ui.makeprogress('other', unit='othernum', total=total)
   >     for i in range(loops):
-  >         ui.progress(topiclabel, i, getloopitem(i), 'loopnum', total)
+  >         progress.update(i, item=getloopitem(i))
   >         if opts.get('parallel'):
-  >             ui.progress('other', i, 'other.%d' % i, 'othernum', total)
+  >             other.update(i, item='other.%d' % i)
   >         if nested:
   >             nested_steps = 2
   >             if i and i % 4 == 0:
   >                 nested_steps = 5
+  >             nested = ui.makeprogress('nested', unit='nestnum',
+  >                                      total=nested_steps)
   >             for j in range(nested_steps):
-  >                 ui.progress(
-  >                   'nested', j, 'nested.%d' % j, 'nestnum', nested_steps)
-  >             ui.progress(
-  >               'nested', None, 'nested.done', 'nestnum', nested_steps)
-  >     ui.progress(topiclabel, None, 'loop.done', 'loopnum', total)
+  >                 nested.update(j, item='nested.%d' % j)
+  >             nested.complete()
+  >     progress.complete()
   > 
   > topiclabel = 'loop'
   > def getloopitem(i):