Disable angle_perftests on Nexus5.

It has been failing for several days.

To reenable, just re-add the lines I removed to perf_data_generator.py
and then rerun tools/perf/generate_perf_data
TBR=jbudorick@chromium.org

Bug: 916824, 915429
Change-Id: I46bb0cd44b1ebf68ccbd6eae79a718c4cf49ee73
Reviewed-on: https://chromium-review.googlesource.com/c/1387832Reviewed-by: Jamie Madill <jmadill@chromium.org>
Cr-Commit-Position: refs/heads/master@{#618668}

testing/buildbot/chromium.perf.json

@@ -3,48 +3,6 @@
   "AAAAA2 See //tools/perf/generate_perf_data to make changes": {},
   "Android Nexus5 Perf": {
     "isolated_scripts": [
-      {
-        "args": [
-          "--gtest-benchmark-name",
-          "angle_perftests",
-          "--non-telemetry=true",
-          "--migrated-test=true",
-          "--shard-timeout=300"
-        ],
-        "isolate_name": "angle_perftests",
-        "merge": {
-          "script": "//tools/perf/process_perf_results.py"
-        },
-        "name": "angle_perftests",
-        "override_compile_targets": [
-          "angle_perftests"
-        ],
-        "swarming": {
-          "can_use_on_swarming_builders": true,
-          "dimension_sets": [
-            {
-              "device_os": "KOT49H",
-              "device_os_flavor": "google",
-              "device_type": "hammerhead",
-              "os": "Android",
-              "pool": "chrome.tests.perf"
-            }
-          ],
-          "expiration": 7200,
-          "hard_timeout": 36000,
-          "ignore_task_failure": false,
-          "io_timeout": 1800,
-          "shards": 1,
-          "upload_test_results": true
-        },
-        "trigger_script": {
-          "args": [
-            "--multiple-dimension-script-verbose",
-            "True"
-          ],
-          "script": "//testing/trigger_scripts/perf_device_trigger.py"
-        }
-      },
       {
         "args": [
           "--gtest-benchmark-name",

tools/perf/core/perf_data_generator.py

@@ -236,14 +236,6 @@ NEW_PERF_RECIPE_MIGRATED_TESTERS = {
           'num_shards': 1,
           'telemetry': False,
         },
-        {
-          'isolate': 'angle_perftests',
-          'num_shards': 1,
-          'telemetry': False,
-          'extra_args': [
-              '--shard-timeout=300'
-          ],
-        }
       ],
       'platform': 'android',
       'dimension': {