[Android] Add context manager to record logcat during step(s).

scripts/slave/recipes/chromium.expected/full_chromium_fyi_Android_Coverage__dbg_.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "chromium.fyi",
       "--builder",
       "Android Coverage (dbg)",
@@ skipping 422 matching lines @@
       "[\"07a00ca4\"]",
       "chromium.fyi",
       "Android Coverage (dbg)",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "spawn_device_monitor"
   },
   {
+    "cmd": [],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "AndroidWebViewTest"
+  },
+  {
+    "cmd": [
+      "[BUILD]/scripts/slave/daemonizer.py",
+      "--",
+      "[SLAVE_BUILD]/src/build/android/adb_logcat_monitor.py",
+      "[TMP_BASE]/test_logcat_tmp_1"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "env": {
+      "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
+    },
+    "name": "AndroidWebViewTest.spawn_logcat_monitor",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
     "cmd": [
       "[SLAVE_BUILD]/src/build/android/adb_install_apk.py",
       "[SLAVE_BUILD]/src/out/Debug/apks/AndroidWebView.apk",
       "-v",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
-    "name": "install AndroidWebView.apk"
+    "name": "AndroidWebViewTest.install AndroidWebView.apk",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/build/android/test_runner.py",
       "instrumentation",
       "--test-apk",
       "[SLAVE_BUILD]/src/out/Debug/apks/AndroidWebViewTest.apk",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json",
       "--apk-under-test",
       "[SLAVE_BUILD]/src/out/Debug/apks/AndroidWebView.apk",
       "--isolate-file-path",
       "android_webview/android_webview_test_apk.isolate",
       "--flakiness-dashboard-server",
       "test-results.appspot.com",
       "--verbose",
       "--coverage-dir",
       "[SLAVE_BUILD]/src/out/Debug/coverage",
       "--json-results-file",
       "/path/to/tmp/json"
     ],
     "cwd": "[SLAVE_BUILD]",
-    "name": "Instrumentation test AndroidWebViewTest",
+    "name": "AndroidWebViewTest.Instrumentation test AndroidWebViewTest",
     "~followup_annotations": [
-      "@@@STEP_TEXT@<br/>failures:<br/>TestB<br/>@@@"
+      "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
+    "cmd": [
+      "python",
+      "-u",
+      "[BUILD]/scripts/slave/tee.py",
+      "/path/to/tmp/logcat",
+      "--",
+      "[SLAVE_BUILD]/src/build/android/adb_logcat_printer.py",
+      "[TMP_BASE]/test_logcat_tmp_1"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "AndroidWebViewTest.logcat_dump",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "ChromePublicTest"
+  },
+  {
+    "cmd": [
+      "[BUILD]/scripts/slave/daemonizer.py",
+      "--",
+      "[SLAVE_BUILD]/src/build/android/adb_logcat_monitor.py",
+      "[TMP_BASE]/test_logcat_tmp_2"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "env": {
+      "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
+    },
+    "name": "ChromePublicTest.spawn_logcat_monitor",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
     "cmd": [
       "[SLAVE_BUILD]/src/build/android/adb_install_apk.py",
       "[SLAVE_BUILD]/src/out/Debug/apks/ChromePublic.apk",
       "-v",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
-    "name": "install ChromePublic.apk"
+    "name": "ChromePublicTest.install ChromePublic.apk",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/build/android/test_runner.py",
       "instrumentation",
       "--test-apk",
       "[SLAVE_BUILD]/src/out/Debug/apks/ChromePublicTest.apk",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json",
       "--apk-under-test",
       "[SLAVE_BUILD]/src/out/Debug/apks/ChromePublic.apk",
       "--isolate-file-path",
       "chrome/chrome_public_test_apk.isolate",
       "--flakiness-dashboard-server",
       "test-results.appspot.com",
       "--verbose",
       "--coverage-dir",
       "[SLAVE_BUILD]/src/out/Debug/coverage",
       "--json-results-file",
       "/path/to/tmp/json"
     ],
     "cwd": "[SLAVE_BUILD]",
-    "name": "Instrumentation test ChromePublicTest",
+    "name": "ChromePublicTest.Instrumentation test ChromePublicTest",
     "~followup_annotations": [
-      "@@@STEP_TEXT@<br/>failures:<br/>TestB<br/>@@@"
+      "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
+    "cmd": [
+      "python",
+      "-u",
+      "[BUILD]/scripts/slave/tee.py",
+      "/path/to/tmp/logcat",
+      "--",
+      "[SLAVE_BUILD]/src/build/android/adb_logcat_printer.py",
+      "[TMP_BASE]/test_logcat_tmp_2"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "ChromePublicTest.logcat_dump",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "ContentShellTest"
+  },
+  {
+    "cmd": [
+      "[BUILD]/scripts/slave/daemonizer.py",
+      "--",
+      "[SLAVE_BUILD]/src/build/android/adb_logcat_monitor.py",
+      "[TMP_BASE]/test_logcat_tmp_3"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "env": {
+      "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
+    },
+    "name": "ContentShellTest.spawn_logcat_monitor",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
     "cmd": [
       "[SLAVE_BUILD]/src/build/android/adb_install_apk.py",
       "[SLAVE_BUILD]/src/out/Debug/apks/ContentShell.apk",
       "-v",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
-    "name": "install ContentShell.apk"
+    "name": "ContentShellTest.install ContentShell.apk",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/build/android/test_runner.py",
       "instrumentation",
       "--test-apk",
       "[SLAVE_BUILD]/src/out/Debug/apks/ContentShellTest.apk",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json",
       "--apk-under-test",
       "[SLAVE_BUILD]/src/out/Debug/apks/ContentShell.apk",
       "--isolate-file-path",
       "content/content_shell_test_apk.isolate",
       "--flakiness-dashboard-server",
       "test-results.appspot.com",
       "--verbose",
       "--coverage-dir",
       "[SLAVE_BUILD]/src/out/Debug/coverage",
       "--json-results-file",
       "/path/to/tmp/json"
     ],
     "cwd": "[SLAVE_BUILD]",
-    "name": "Instrumentation test ContentShellTest",
+    "name": "ContentShellTest.Instrumentation test ContentShellTest",
     "~followup_annotations": [
-      "@@@STEP_TEXT@<br/>failures:<br/>TestB<br/>@@@"
+      "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
+    "cmd": [
+      "python",
+      "-u",
+      "[BUILD]/scripts/slave/tee.py",
+      "/path/to/tmp/logcat",
+      "--",
+      "[SLAVE_BUILD]/src/build/android/adb_logcat_printer.py",
+      "[TMP_BASE]/test_logcat_tmp_3"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "ContentShellTest.logcat_dump",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "ChromeSyncShellTest"
+  },
+  {
+    "cmd": [
+      "[BUILD]/scripts/slave/daemonizer.py",
+      "--",
+      "[SLAVE_BUILD]/src/build/android/adb_logcat_monitor.py",
+      "[TMP_BASE]/test_logcat_tmp_4"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "env": {
+      "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
+    },
+    "name": "ChromeSyncShellTest.spawn_logcat_monitor",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
     "cmd": [
       "[SLAVE_BUILD]/src/build/android/adb_install_apk.py",
       "[SLAVE_BUILD]/src/out/Debug/apks/ChromeSyncShell.apk",
       "-v",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
-    "name": "install ChromeSyncShell.apk"
+    "name": "ChromeSyncShellTest.install ChromeSyncShell.apk",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/build/android/test_runner.py",
       "instrumentation",
       "--test-apk",
       "[SLAVE_BUILD]/src/out/Debug/apks/ChromeSyncShellTest.apk",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json",
       "--apk-under-test",
       "[SLAVE_BUILD]/src/out/Debug/apks/ChromeSyncShell.apk",
       "--flakiness-dashboard-server",
       "test-results.appspot.com",
       "--verbose",
       "--coverage-dir",
       "[SLAVE_BUILD]/src/out/Debug/coverage",
       "--json-results-file",
       "/path/to/tmp/json"
     ],
     "cwd": "[SLAVE_BUILD]",
-    "name": "Instrumentation test ChromeSyncShellTest",
+    "name": "ChromeSyncShellTest.Instrumentation test ChromeSyncShellTest",
     "~followup_annotations": [
-      "@@@STEP_TEXT@<br/>failures:<br/>TestB<br/>@@@"
+      "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
+    "cmd": [
+      "python",
+      "-u",
+      "[BUILD]/scripts/slave/tee.py",
+      "/path/to/tmp/logcat",
+      "--",
+      "[SLAVE_BUILD]/src/build/android/adb_logcat_printer.py",
+      "[TMP_BASE]/test_logcat_tmp_4"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "ChromeSyncShellTest.logcat_dump",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/build/android/generate_emma_html.py",
       "--coverage-dir",
       "[SLAVE_BUILD]/src/out/Debug/coverage",
       "--metadata-dir",
       "[SLAVE_BUILD]/src/out/Debug",
       "--cleanup",
       "--output",
@@ skipping 96 matching lines @@
     "cwd": "[SLAVE_BUILD]/src",
     "name": "Finding lines changed in modified file fake/file3.java",
     "stdout": "/path/to/tmp/"
   },
   {
     "cmd": [
       "python",
       "-u",
       "\nimport shutil\nimport sys\nshutil.copy(sys.argv[1], sys.argv[2])\n",
       "{\"fake/file1.java\": [], \"fake/file2.java;\": [], \"fake/file3.java\": []}",
-      "[TMP_BASE]/coverage_tmp_1/file_changes.json"
+      "[TMP_BASE]/coverage_tmp_5/file_changes.json"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "Saving changed lines for revision."
   },
   {
     "cmd": [
       "python",
       "-u",
       "build/android/emma_coverage_stats.py",
       "-v",
       "--out",
       "/path/to/tmp/json",
       "--emma-dir",
       "[SLAVE_BUILD]/src/out/Debug/coverage/coverage_html",
       "--lines-for-coverage",
-      "[TMP_BASE]/coverage_tmp_1/file_changes.json"
+      "[TMP_BASE]/coverage_tmp_5/file_changes.json"
     ],
     "cwd": "[SLAVE_BUILD]/src",
     "name": "Incremental coverage report",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"files\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"sample file 1\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"absolute\": {@@@",
       "@@@STEP_LOG_LINE@json.output@        \"covered\": 70, @@@",
       "@@@STEP_LOG_LINE@json.output@        \"total\": 100@@@",
@@ skipping 98 matching lines @@
       "@@@STEP_LOG_LINE@python.inline@  os.remove(report)@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]