Add dependency for bindings/*/v8:testing

Certain source files here depend on generated core files, such as
core/css/css_property_names.h . Expressing this dependency without
causing linker errors is tricky. This solution is based on CL:2489922.

Bug: 1140604
Change-Id: I91932db7d3df4ce517950e0bd2c747e4468cef69
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2488560
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819657}

third_party/blink/renderer/bindings/core/v8/BUILD.gn

@@ -62,6 +62,7 @@ source_set("testing") {
   deps = [
     ":generated",
     ":testing_internal",
+    "//third_party/blink/renderer/core",
     "//third_party/blink/renderer/platform",
     "//v8",
   ]

third_party/blink/renderer/bindings/modules/v8/BUILD.gn

@@ -60,6 +60,8 @@ source_set("testing") {
 
   deps = [
     ":generated",
+    "//third_party/blink/renderer/core",
+    "//third_party/blink/renderer/modules",
     "//third_party/blink/renderer/platform",
     "//v8",
   ]