vm_run_skia_try/write_json_summary: run skpdiff within imagediffdb, not on its own

compute_engine_scripts/telemetry/telemetry_slave_scripts/test_data/summary.json

Index: compute_engine_scripts/telemetry/telemetry_slave_scripts/test_data/summary.json
diff --git a/compute_engine_scripts/telemetry/telemetry_slave_scripts/test_data/summary.json b/compute_engine_scripts/telemetry/telemetry_slave_scripts/test_data/summary.json
index 0ad876f71c105ee40ffa7fb2ad76d56050d0459a..493260ecedca3f6dd4e5aae21ac96a6821b25f29 100644
--- a/compute_engine_scripts/telemetry/telemetry_slave_scripts/test_data/summary.json
+++ b/compute_engine_scripts/telemetry/telemetry_slave_scripts/test_data/summary.json
@@ -6,7 +6,7 @@
                 "maxDiffPerChannel": 4, 
                 "numPixelsDiffering": 1, 
                 "percentPixelsDiffering": 2, 
-                "perceptualSimilarity": 0.3, 
+                "perceptualSimilarity": 5, 

[epoger, 2014/03/03 21:51:05]

Now that perceptualSimilarity is being provided by imagediffdb_mock, it has a
consistent value like the other fields.

[rmistry, 2014/03/04 13:14:19]

Acknowledged. (Rietveld needs an 'Ack' button, I should add it).

[epoger, 2014/03/04 14:44:42]

Ack.

Ack-tually, I guess it would also work for us to use the abbreviation "ack"
along with SGTM, etc.  Just clicking a button is faster, but a short word ain't
too bad.

                 "skpLocation": "gs://dummy-bucket/skps/file_.skp", 
                 "weightedDiffMeasure": 3
             }, 
@@ -15,7 +15,7 @@
                 "maxDiffPerChannel": 4, 
                 "numPixelsDiffering": 1, 
                 "percentPixelsDiffering": 2, 
-                "perceptualSimilarity": 0.1, 
+                "perceptualSimilarity": 5, 
                 "skpLocation": "gs://dummy-bucket/skps/file_.skp", 
                 "weightedDiffMeasure": 3
             }