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

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

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "chromium.fyi",
       "--builder",
       "ClangToTAndroidASan tester",
@@ skipping 464 matching lines @@
     "env": {
       "LLVM_FORCE_HEAD_REVISION": "YES",
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
     "name": "base_junit_tests",
     "~followup_annotations": [
       "@@@STEP_TEXT@<br/>failures:<br/>TestB<br/>@@@"
     ]
   },
   {
+    "cmd": [],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "components_browsertests"
+  },
+  {
+    "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": {
+      "LLVM_FORCE_HEAD_REVISION": "YES",
+      "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
+    },
+    "name": "components_browsertests.spawn_logcat_monitor",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/build/android/test_runner.py",
       "gtest",
       "-s",
       "components_browsertests",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json",
       "--verbose",
       "--isolate_file_path=[SLAVE_BUILD]/src/components/components_browsertests.isolate",
       "--tool=asan",
       "--flakiness-dashboard-server=test-results.appspot.com",
       "--json-results-file",
       "/path/to/tmp/json"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
       "LLVM_FORCE_HEAD_REVISION": "YES",
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
-    "name": "components_browsertests"
+    "name": "components_browsertests.components_browsertests",
+    "~followup_annotations": [
+      "@@@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": "components_browsertests.logcat_dump",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "gfx_unittests"
+  },
+  {
+    "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": {
+      "LLVM_FORCE_HEAD_REVISION": "YES",
+      "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
+    },
+    "name": "gfx_unittests.spawn_logcat_monitor",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/build/android/test_runner.py",
       "gtest",
       "-s",
       "gfx_unittests",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json",
       "--verbose",
       "--tool=asan",
       "--flakiness-dashboard-server=test-results.appspot.com",
       "--json-results-file",
       "/path/to/tmp/json"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
       "LLVM_FORCE_HEAD_REVISION": "YES",
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
-    "name": "gfx_unittests"
+    "name": "gfx_unittests.gfx_unittests",
+    "~followup_annotations": [
+      "@@@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": "gfx_unittests.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_3"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "env": {
+      "LLVM_FORCE_HEAD_REVISION": "YES",
+      "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": {
       "LLVM_FORCE_HEAD_REVISION": "YES",
       "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",
       "--tool=asan",
       "--flakiness-dashboard-server",
       "test-results.appspot.com",
       "--verbose",
       "--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_3"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "ChromePublicTest.logcat_dump",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/daemonizer.py",
       "--action",
       "stop",
       "--pid-file-path",
       "/tmp/device_monitor.pid"
     ],
     "cwd": "[SLAVE_BUILD]",
@@ skipping 73 matching lines @@
       "@@@STEP_LOG_LINE@python.inline@  os.remove(report)@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]