Revert of [GN] Set v8_use_external_snapshot_data for the same configurations as GN.

Revert of [GN] Set v8_use_external_snapshot_data for the same configurations as GN. (patchset #2 id:40001 of https://codereview.chromium.org/796903002/)

Reason for revert:
Seems to have broken the Android GN build:
http://build.chromium.org/p/chromium.linux/builders/Android%20GN/builds/14937
http://build.chromium.org/p/chromium.linux/builders/Android%20GN/builds/14938

Original issue's description:
> [GN] Set v8_use_external_snapshot_data for the same configurations as GN.
> 
> BUG=421063
> 
> Committed: https://crrev.com/def2eb00493259ff297e8792fee35dc7dc2204b5
> Cr-Commit-Position: refs/heads/master@{#308779}

TBR=brettw@chromium.org,rmcilroy@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=421063

[Marc Treib, 2014-12-17 12:13:08]

Created Revert of [GN] Set v8_use_external_snapshot_data for the same
configurations as GN.

[commit-bot: I haz the power, 2014-12-17 12:13:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/805333003/1

[Marc Treib, 2014-12-17 12:14:43]

The CQ bit was unchecked by treib@chromium.org

[commit-bot: I haz the power, 2014-12-17 12:14:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-12-17 12:14:46]

Failed to apply patch for net/BUILD.gn:
While running git apply --index -3 -p1;
  error: patch failed: net/BUILD.gn:5
  error: repository lacks the necessary blob to fall back on 3-way merge.
  error: net/BUILD.gn: patch does not apply

Patch:       net/BUILD.gn
Index: net/BUILD.gn
diff --git a/net/BUILD.gn b/net/BUILD.gn
index
f0de5a354ca3962cb92586ef0804c51c9b38c01f..73eb465851fa9ee85c17000848b843b0f5479119
100644
--- a/net/BUILD.gn
+++ b/net/BUILD.gn
@@ -5,7 +5,6 @@
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
-import("//build/module_args/v8.gni")
 import("//url/config.gni")
 
 # TODO(cjhopman): //build/config/android/rules.gni also imports grit_rule.gni.
@@ -1182,10 +1181,6 @@
       ]
     }
 
-    if (v8_use_external_startup_data) {
-      deps += [ "//gin" ]
-    }
-
     if (!use_nss_certs) {
       sources -= [ "ssl/client_cert_store_nss_unittest.cc" ]
       if (is_chromeos) {  # Already removed for all non-ChromeOS builds.

[Marc Treib, 2014-12-17 12:15:56]

rmcilroy was faster: https://codereview.chromium.org/808833003/
Closing this one.