Remove android_webview_build conditions from various places.

Remove various minor android_webview_build references now that we no
longer support that build configuration.

BUG=440793

Review URL: https://codereview.chromium.org/1048863002

Cr-Commit-Position: refs/heads/master@{#324078}
diff --git a/net/BUILD.gn b/net/BUILD.gn
index 51c5fc0..eaf01d2 100644
--- a/net/BUILD.gn
+++ b/net/BUILD.gn
@@ -507,10 +507,7 @@
       "base/platform_mime_util_linux.cc",
     ]
     set_sources_assignment_filter(sources_assignment_filter)
-
-    if (!is_android_webview_build) {
-      deps += [ ":net_jni_headers" ]
-    }
+    deps += [ ":net_jni_headers" ]
   }
 
   if (use_icu_alternatives_on_android) {