Windows GN tests, webcrypto warnings

Enables many GN Windows tests.

The GN build wasn't disabling the size_t to int warning in webcrypto. I decided to fix the warnings rather than disable them. This code is a random mishmash of size_t, int, unsigned, and long (partially due to third party code). In this change, I tried to do something minimal and clear: some variables were changed to size_t, while some were converted to casts.

CQ_EXTRA_TRYBOTS=tryserver.chromium.linux:android_chromium_gn_compile_dbg,android_chromium_gn_compile_rel;tryserver.chromium.win:win8_chromium_gn_rel,win8_chromium_gn_dbg

TBR=dpranke

Review URL: https://codereview.chromium.org/1091293003

Cr-Commit-Position: refs/heads/master@{#326046}
diff --git a/net/BUILD.gn b/net/BUILD.gn
index b425371..0f6cbbb 100644
--- a/net/BUILD.gn
+++ b/net/BUILD.gn
@@ -1317,9 +1317,8 @@
 }
 
 # TODO(GYP) make this compile on Android, we need some native test deps done.
-# TODO(GYP) Also doesn't work on Windows; dependency on boringssl is wrong.
 # TODO(GYP) Also doesn't work on Mac, need to figure out why not.
-if (!is_android && !is_win && !is_mac) {
+if (!is_android && !is_mac) {
   test("net_unittests") {
     sources = gypi_values.net_test_sources
 
@@ -1328,11 +1327,11 @@
     defines = []
 
     deps = [
+      ":balsa",
       ":extras",
       ":http_server",
       ":net",
       ":net_quic_proto",
-      ":epoll_quic_tools",
       ":simple_quic_tools",
       ":test_support",
       "//base",
@@ -1352,6 +1351,9 @@
       "//url",
     ]
 
+    if (is_desktop_linux) {
+      deps += [ ":epoll_quic_tools" ]
+    }
     if (is_linux) {
       sources += gypi_values.net_linux_test_sources
       deps += [