Remove content/browser dependency on WebFontRenderStyle.

It's only called by the renderer, but was put in a utilities file in content/common that was shared with other methods that are called from the browser. Fix this by splitting the common method from the child-only ones.

BUG=248653

Review-Url: https://codereview.chromium.org/2679323006
Cr-Commit-Position: refs/heads/master@{#449672}
diff --git a/content/common/BUILD.gn b/content/common/BUILD.gn
index 1a72679..5c9e9c78 100644
--- a/content/common/BUILD.gn
+++ b/content/common/BUILD.gn
@@ -64,11 +64,9 @@
     "child_process_host_impl.cc",
     "child_process_host_impl.h",
     "child_process_messages.h",
-    "child_process_sandbox_support_impl_linux.cc",
-    "child_process_sandbox_support_impl_linux.h",
-    "child_process_sandbox_support_impl_shm_linux.cc",
     "clipboard_format.h",
     "clipboard_messages.h",
+    "common_sandbox_support_linux.cc",
     "content_constants_internal.cc",
     "content_constants_internal.h",
     "content_export.h",