Remove remote tree host and some related input and metro_driver code

ash/ash_unittests.isolate

Index: ash/ash_unittests.isolate
diff --git a/ash/ash_unittests.isolate b/ash/ash_unittests.isolate
index a210ff87cae90c0cfdb27e90c962a21008600a28..89ab132b78c3828112f83cff1297088419519244 100644
--- a/ash/ash_unittests.isolate
+++ b/ash/ash_unittests.isolate
@@ -26,7 +26,7 @@
         ],
       },
     }],
-    ['OS=="win" or chromeos==1', {
+    ['chromeos==1', {
       'variables': {
         'files': [
           '../testing/test_env.py',
@@ -52,20 +52,6 @@
         ],
       },
     }],
-    ['OS=="win"', {
-      'variables': {
-        'files': [
-          '<(PRODUCT_DIR)/osmesa.dll',
-        ],
-      },
-    }],
-    ['OS=="win" and (fastbuild==0 or fastbuild==1)', {
-      'variables': {
-        'files': [
-          '<(PRODUCT_DIR)/ash_unittests.exe.pdb',
-        ],
-      },
-    }],
   ],
   'includes': [
     '../base/base.isolate',