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

scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Android__Nexus4_.json

Index: scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Android__Nexus4_.json
diff --git a/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Android__Nexus4_.json b/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Android__Nexus4_.json
index 4946e9f82c5e870fc86e836c045d503a0caba6e0..d647c928f08fe018fd96d65538718bfb4ee02d90 100644
--- a/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Android__Nexus4_.json
+++ b/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Android__Nexus4_.json
@@ -442,6 +442,27 @@
     "name": "spawn_device_monitor"
   },
   {
+    "cmd": [],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "blink_heap_unittests"
+  },
+  {
+    "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": "blink_heap_unittests.spawn_logcat_monitor",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
     "cmd": [
       "python",
       "-u",
@@ -461,7 +482,47 @@
     "env": {
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
-    "name": "blink_heap_unittests"
+    "name": "blink_heap_unittests.blink_heap_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_1"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "blink_heap_unittests.logcat_dump",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "webkit_unit_tests"
+  },
+  {
+    "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": "webkit_unit_tests.spawn_logcat_monitor",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "cmd": [
@@ -483,7 +544,26 @@
     "env": {
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
-    "name": "webkit_unit_tests"
+    "name": "webkit_unit_tests.webkit_unit_tests",
+    "~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": "webkit_unit_tests.logcat_dump",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "cmd": [