Use framework style includes in ios/web_view/public.

build/config/ios/rules.gni

Index: build/config/ios/rules.gni
diff --git a/build/config/ios/rules.gni b/build/config/ios/rules.gni
index 11bcd5cda930c3246ceae40420ac52379d816e0d..2cafb96c34f318713353fc42b56220da56699855 100644
--- a/build/config/ios/rules.gni
+++ b/build/config/ios/rules.gni
@@ -1169,6 +1169,12 @@ template("ios_framework_bundle") {
       _compile_headers_map_target = _target_name + "_compile_headers_map"
       action(_compile_headers_map_target) {
         visibility = [ ":$_framework_headers_target" ]
+        forward_variables_from(invoker,
+                               [
+                                 "deps",
+                                 "public_deps",
+                                 "testonly",
+                               ])
         script = "//build/config/ios/write_framework_hmap.py"
         outputs = [
           _header_map_filename,
@@ -1214,6 +1220,7 @@ template("ios_framework_bundle") {
       }
 
       group(_framework_headers_target) {
+        forward_variables_from(invoker, [ "testonly" ])
         deps = [
           ":$_compile_headers_map_target",
           ":$_copy_public_headers_target",