V8 Buildbot: Let leak checker use the v8-side wrapper.

scripts/slave/recipes/v8.expected/full_client_v8_V8_Linux64___memcheck.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "client.v8",
       "--builder",
-      "V8 Linux - memcheck",
+      "V8 Linux64 - memcheck",
       "--slave",
       "TestSlavename",
       "--spec",
-      "cache_dir = None\nsolutions = [{'custom_vars': {'chromium_trunk': 'svn://svn-mirror.golo.chromium.org/chrome/trunk'}, 'deps_file': 'DEPS', 'managed': True, 'name': 'v8', 'url': 'https://chromium.googlesource.com/v8/v8'}]",
+      "cache_dir = None\nsolutions = [{'custom_deps': {'v8/third_party/valgrind': 'https://chromium.googlesource.com/chromium/deps/valgrind/binaries.git'}, 'custom_vars': {'chromium_trunk': 'svn://svn-mirror.golo.chromium.org/chrome/trunk'}, 'deps_file': 'DEPS', 'managed': True, 'name': 'v8', 'url': 'https://chromium.googlesource.com/v8/v8'}]",
       "--root",
       "v8",
       "--revision_mapping_file",
       "{\"v8\": \"got_revision\"}",
       "--output_json",
       "/path/to/tmp/json",
       "--revision",
       "v8@54321",
       "--no_shallow",
       "--output_manifest"
@@ skipping 26 matching lines @@
   },
   {
     "cmd": [
       "python",
       "-u",
       "[DEPOT_TOOLS]/gclient.py",
       "runhooks"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
-      "GYP_DEFINES": "target_arch=ia32 v8_enable_slow_dchecks=1 v8_optimized_debug=1 v8_target_arch=ia32"
+      "GYP_DEFINES": "target_arch=x64 v8_enable_slow_dchecks=1 v8_optimized_debug=1 v8_target_arch=x64"
     },
     "name": "gclient runhooks"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/cleanup_temp.py"
     ],
     "cwd": "[SLAVE_BUILD]",
@@ skipping 19 matching lines @@
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/extract_build.py",
       "--target",
       "Debug",
       "--build-url",
-      "gs://chromium-v8/v8-linux-dbg",
+      "gs://chromium-v8/v8-linux64-dbg",
       "--src-dir",
       "v8",
       "--master-name",
       "client.v8",
       "--build-number",
       "571"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "extract build"
   },
   {
     "cmd": [
-      "valgrind",
-      "--leak-check=full",
-      "--show-reachable=yes",
-      "--num-callers=20",
+      "python",
+      "-u",
+      "[SLAVE_BUILD]/v8/tools/run-valgrind.py",
       "out/Debug/d8",
       "-e",
-      "\"print(1+2)\""
+      "print(1+2)"
     ],
     "cwd": "[SLAVE_BUILD]/v8",
-    "name": "Simple Leak Check",
-    "stderr": "/path/to/tmp/",
-    "~followup_annotations": [
-      "@@@STEP_LOG_LINE@stderr@no leaks are possible@@@",
-      "@@@STEP_LOG_END@stderr@@@"
-    ]
+    "name": "Simple Leak Check"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]