Deletes bench_expectations.txt and change comments to refer to the new per-bot expectation files.

Review URL: https://codereview.chromium.org/23830009

git-svn-id: http://skia.googlecode.com/svn/trunk@11456 2bbb7eff-a529-9590-31e7-b0007b416f81

bench/bench_graph_svg.py

@@ -32,9 +32,9 @@ def usage():
     print '-b <bench> the bench to show.'
     print '-c <config> the config to show (GPU, 8888, 565, etc).'
     print '-d <dir> a directory containing bench_r<revision>_<scalar> files.'
-    print '-e <file> file containing expected bench values/ranges.'
+    print '-e <file> file containing expected bench builder values/ranges.'
     print '   Will raise exception if actual bench values are out of range.'
-    print '   See bench_expectations.txt for data format and examples.'
+    print '   See bench_expectations_<builder>.txt for data format / examples.'
     print '-f <revision>[:<revision>] the revisions to use for fitting.'
     print '   Negative <revision> is taken as offset from most recent revision.'
     print '-i <time> the time to ignore (w, c, g, etc).'

bench/gen_bench_ranges.py

@@ -5,13 +5,13 @@
 
 """ Analyze recent SkPicture or Microbench data, and output suggested ranges.
 
-The outputs can be edited and pasted to bench_expectations.txt to trigger
-buildbot alerts if the actual benches are out of range. Details are documented
-in the .txt file.
+The outputs can be edited and pasted to bench_expectations_<builder>.txt to
+trigger buildbot alerts if the actual benches are out of range. Details are
+documented in the corresponding .txt file for each builder.
 
-Currently the easiest way to batch update bench_expectations.txt is to delete
-all bench lines, run this script, and redirect outputs (">>") to be added to the
-.txt file.
+Currently the easiest way to batch update bench_expectations_<builder>.txt is to
+delete all bench lines, run this script, and redirect outputs (">>") to be added
+to the corresponding .txt file for each perf builder.
 You can also just manually change a few lines of interest, of course.
 
 Note: since input data are stored in Google Storage, you will need to set up