Revert of Move (hopefully) remaining isolate related variables to...

Revert of Move (hopefully) remaining isolate related variables to toolchain.gypi (patchset #1 id:1 of https://codereview.chromium.org/2027213002/ )

Reason for revert:
Fails:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/7182/steps/gclient%20runhooks/logs/stdio

Original issue's description:
> Move (hopefully) remaining isolate related variables to toolchain.gypi
>
> BUG=chromium:609107
> R=machenbach@chromium.org
>
> Committed: https://crrev.com/a68a1eb38dda0a1eba3b7644a172d2f85e9c7abe
> Cr-Commit-Position: refs/heads/master@{#36664}

TBR=jochen@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:609107

Review-Url: https://codereview.chromium.org/2038463002
Cr-Commit-Position: refs/heads/master@{#36665}

gypfiles/standalone.gypi

@@ -112,6 +112,9 @@
       'use_goma%': 0,
       'gomadir%': '',
 
+      # Check if valgrind directories are present.
+      'has_valgrind%': '<!pymod_do_main(has_valgrind)',
+
       'test_isolation_mode%': 'noop',
 
       'conditions': [
@@ -161,6 +164,7 @@
     'test_isolation_mode%': '<(test_isolation_mode)',
     'fastbuild%': '<(fastbuild)',
     'coverage%': '<(coverage)',
+    'has_valgrind%': '<(has_valgrind)',
 
     # Add a simple extras solely for the purpose of the cctests
     'v8_extra_library_files': ['../test/cctest/test-extra.js'],

gypfiles/toolchain.gypi

@@ -29,19 +29,6 @@
 
 {
   'variables': {
-    'variables': {
-      'variables': {
-        # Instrument for code coverage and use coverage wrapper to exclude some
-        # files. Uses gcov if clang=0 is set explicitly. Otherwise,
-        # sanitizer_coverage must be set too.
-        'coverage%': 0,
-      },
-
-      'coverage%': '<(coverage)',
-
-      # Check if valgrind directories are present.
-      'has_valgrind%': '<!pymod_do_main(has_valgrind)',
-    },
     'msvs_use_common_release': 0,
     'clang%': 0,
     'asan%': 0,
@@ -50,8 +37,6 @@
     'tsan%': 0,
     'ubsan%': 0,
     'ubsan_vptr%': 0,
-    'has_valgrind%': '<(has_valgrind)',
-    'coverage%': '<(coverage)',
     'v8_target_arch%': '<(target_arch)',
     'v8_host_byteorder%': '<!(python -c "import sys; print sys.byteorder")',
     # Native Client builds currently use the V8 ARM JIT and