[code coverage] Fix and clean up test suites of linux-code-coverage

This CL does two things:
1. Fix the test suites of linux-code-coverage to match that of
   "Linux Tests".
2. Cleans up unneeded fuzzer bits.

Bug: 1016929
Change-Id: I5cc2d1d9b1e5b71443ce917377fedaaee122b770
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1974617Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Yuke Liao <liaoyuke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726279}

testing/buildbot/test_suite_exceptions.pyl

@@ -104,6 +104,11 @@
     ],
     'modifications': {
       # chromium.fyi
+      'linux-code-coverage': {
+        'swarming': {
+          'shards': 21,
+        },
+      },
       'linux-chromeos-code-coverage': {
         'swarming': {
           'shards': 21,
@@ -1310,6 +1315,11 @@
   'non_viz_browser_tests': {
     'modifications': {
       # chromium.fyi
+      'linux-code-coverage': {
+        'swarming': {
+          'shards': 21,
+        },
+      },
       'linux-chromeos-code-coverage': {
         'swarming': {
           'shards': 20,
@@ -1370,6 +1380,15 @@
       'Linux Tests (dbg)(1)',
     ],
     'modifications': {
+      'linux-code-coverage': {
+        'args': [
+          '--additional-env-var=LLVM_PROFILE_FILE=${ISOLATED_OUTDIR}/profraw/default-%2m.profraw',
+          '--fuzzy-diff',
+        ],
+        'swarming': {
+          'shards': 20,
+        },
+      },
       'Linux Tests': {
         "args": [
           "--additional-env-var=LLVM_PROFILE_FILE=${ISOLATED_OUTDIR}/profraw/default-%2m.profraw",
@@ -2043,6 +2062,15 @@
           '--fuzzy-diff',
         ],
       },
+      'linux-code-coverage': {
+        'args': [
+          '--additional-env-var=LLVM_PROFILE_FILE=${ISOLATED_OUTDIR}/profraw/default-%2m.profraw',
+          '--fuzzy-diff',
+        ],
+        'swarming': {
+          'shards': 20,
+        },
+      },
       # chromium.linux
       'Fuchsia x64': {
         'args': [

testing/buildbot/waterfalls.pyl

@@ -1905,9 +1905,10 @@
           'linux-xenial',
         ],
         'test_suites': {
-          'gtest_tests': 'chromium_linux_coverage_gtests',
-          'isolated_scripts': 'chromium_code_coverage_isolated_scripts_and_fuzzers',
-        }
+          'gtest_tests': 'chromium_linux_gtests',
+          'isolated_scripts': 'chromium_linux_rel_isolated_scripts',
+          'scripts': 'chromium_linux_scripts',
+        },
       },
       'linux-fieldtrial-rel': {
         'mixins': [

tools/mb/mb.py

@@ -1144,7 +1144,6 @@ class MetaBuildWrapper(object):
             target + '.runtime_deps',
             stamp_runtime_deps]
       elif (target_type == 'script' or
-            target_type == 'fuzzer' or
             isolate_map[target].get('label_type') == 'group'):
         # For script targets, the build target is usually a group,
         # for which gn generates the runtime_deps next to the stamp file
@@ -1449,13 +1448,6 @@ class MetaBuildWrapper(object):
           '../../testing/test_env.py',
           script,
       ]
-    elif test_type == 'fuzzer':
-      cmdline += [
-        '../../testing/test_env.py',
-        '../../tools/code_coverage/run_fuzz_target.py',
-        '--fuzzer', './' + target,
-        '--output-dir', '${ISOLATED_OUTDIR}',
-        '--timeout', '3600']
     elif is_android and test_type != "script":
       if asan:
         cmdline += [os.path.join('bin', 'run_with_asan'), '--']

tools/mb/mb_unittest.py

@@ -523,42 +523,6 @@ class UnitTest(unittest.TestCase):
     self.assertIn('/fake_src/out/Default/cc_perftests.isolated.gen.json',
                   mbw.files)
 
-  def test_gen_fuzzer(self):
-    files = {
-      '/tmp/swarming_targets': 'cc_perftests_fuzzer\n',
-      '/fake_src/testing/buildbot/gn_isolate_map.pyl': (
-          "{'cc_perftests_fuzzer': {"
-          "  'label': '//cc:cc_perftests_fuzzer',"
-          "  'type': 'fuzzer',"
-          "}}\n"
-      ),
-    }
-
-    mbw = self.fake_mbw(files=files)
-
-    def fake_call(cmd, env=None, buffer_output=True, stdin=None):
-      del cmd
-      del env
-      del buffer_output
-      del stdin
-      mbw.files['/fake_src/out/Default/cc_perftests_fuzzer.runtime_deps'] = (
-          'cc_perftests_fuzzer\n')
-      return 0, '', ''
-
-    mbw.Call = fake_call
-
-    self.check(['gen',
-                '-c', 'debug_goma',
-                '--swarming-targets-file', '/tmp/swarming_targets',
-                '--isolate-map-file',
-                '/fake_src/testing/buildbot/gn_isolate_map.pyl',
-                '//out/Default'], mbw=mbw, ret=0)
-    self.assertIn('/fake_src/out/Default/cc_perftests_fuzzer.isolate',
-                  mbw.files)
-    self.assertIn(
-        '/fake_src/out/Default/cc_perftests_fuzzer.isolated.gen.json',
-        mbw.files)
-
   def test_multiple_isolate_maps(self):
     files = {
       '/tmp/swarming_targets': 'cc_perftests\n',