cli: Don't rely on image generation for diff-image tests.

Use static images instead.

Author: jrfonseca

cli/cli-diff-images-mismatch.script

@@ -1,18 +1,7 @@
-# The first two steps are just as in cli-diff-images. Dump images from
-# a trace into an empty directory.
-
-rm_and_mkdir ./tri-out
-apitrace dump-images --call-nos=no -o ./tri-out/tri tri.trace
-
-# Compare the dumped image with a doctored image to provoke a failure.
-# The EXPECT_FAILURE attribute causes the test driver to look for a
-# non-zero return value from apitrace and fail the test if it is not
-# seen.
-
-EXPECT_FAILURE: apitrace diff-images -v ./tri-ref-mismatch ./tri-out
+EXPECT_FAILURE: apitrace diff-images --verbose images/white-1x1/ images/black-1x1/
 
 # In addition to getting the return value indicating an error, let's
 # also require that "apitrace diff-images" gave us the output we
 # expect.
 
-expect "Comparing ./tri-ref-mismatch/tri0000000000.png and ./tri-out/tri0000000000.png ... MISMATCH\n"
+expect "Comparing images/white-1x1/0.png and images/black-1x1/0.png ... MISMATCH\n"

cli/cli-diff-images.script

@@ -1,18 +1,8 @@
-# Make a directory for the output images
-
-rm_and_mkdir ./tri-out
-
-# Generate images for every frame (only 1) of a trace
-
-apitrace dump-images --call-nos=no -o ./tri-out/tri tri.trace
-
-# Compare the result of "apitrace dump-images" with our reference
-
-apitrace diff-images -v ./tri-ref ./tri-out
+apitrace diff-images --verbose images/white-1x1/ images/white-1x1/
 
 # Ensure that the "apitrace diff-images" actually did something.  This
 # is important since if it couldn't find images in one directory or
 # the other then it would just silently return 0 and this test would
 # incorrectly pass.
 
-expect "Comparing ./tri-ref/tri0000000000.png and ./tri-out/tri0000000000.png ... MATCH\n"
+expect "Comparing images/white-1x1/0.png and images/white-1x1/0.png ... MATCH\n"