Revert "[ios] Update application extension rpath"

This reverts commit 7f416325.

Reason for revert: the ios-simulator-cronet builder is failing because of that change

Original change's description:
> [ios] Update application extension rpath
> 
> As application extension may share private frameworks with the app
> they are bundled in, the rpath needs to look both in the extension
> private frameworks and the app private frameworks.
> 
> Bug: none
> Change-Id: I5686d20d8e3f131929ec14caa932bda18bf7d517
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2201096
> Reviewed-by: David Jean <djean@chromium.org>
> Reviewed-by: Javier Ernesto Flores Robles <javierrobles@chromium.org>
> Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#768745}

TBR=sdefresne@chromium.org,javierrobles@chromium.org,djean@chromium.org

Change-Id: Ie83c0aca04c83581ef9bd0bcbff992d9449cc0d1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: none
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2201601Reviewed-by: Amr Aboelkher <amraboelkher@google.com>
Commit-Queue: Amr Aboelkher <amraboelkher@google.com>
Cr-Commit-Position: refs/heads/master@{#768759}

build/config/ios/rules.gni

@@ -512,10 +512,13 @@ template("ios_info_plist") {
 #       entitlements (must generate a single file as output); cannot be
 #       defined if entitlements_path is set.
 #
+#   bundle_extension:
+#       (optional) bundle extension including the dot, default to ".app".
+#
 #   product_type
 #       (optional) string, product type for the generated Xcode project,
-#       default to "com.apple.product-type.application". Should only be
-#       overriden when building application extension.
+#       default to "com.apple.product-type.application". Should generally
+#       not be overridden.
 #
 #   enable_code_signing
 #       (optional) boolean, control whether code signing is enabled or not,
@@ -630,25 +633,6 @@ template("ios_app_bundle") {
                        "target_out_dir") + "/$_output_name.xcent"
   }
 
-  _app_product_type = "com.apple.product-type.application"
-  _appex_product_type = "com.apple.product-type.app-extension"
-  not_needed([ "_appex_product_type" ])
-
-  _product_type = _app_product_type
-  if (defined(invoker.product_type)) {
-    _product_type = invoker.product_type
-  }
-
-  if (_product_type == _app_product_type) {
-    _bundle_extension = ".app"
-  } else if (_product_type == _appex_product_type) {
-    _bundle_extension = ".appex"
-  } else {
-    assert(false, "unknown product_type \"$product_type\" for $_target_name")
-  }
-
-  _is_app_framework = _product_type == _app_product_type
-
   executable(_arch_executable_target) {
     forward_variables_from(invoker,
                            "*",
@@ -698,18 +682,6 @@ template("ios_app_bundle") {
       "2",
     ]
 
-    # Application extension may share private frameworks with the application
-    # itself, so they need to look in both their own bundle and the surrounding
-    # app bundle for the frameworks.
-    if (!_is_app_framework) {
-      ldflags += [
-        "-Xlinker",
-        "-rpath",
-        "-Xlinker",
-        "@executable_path/../../Frameworks",
-      ]
-    }
-
     if (use_ios_simulator) {
       deps += [ ":$_generate_entitlements_target($default_toolchain)" ]
 
@@ -820,8 +792,24 @@ template("ios_app_bundle") {
       }
     }
 
-    # Only write PkgInfo for real application, not application extension.
-    if (_is_app_framework) {
+    _app_product_type = "com.apple.product-type.application"
+    _product_type = _app_product_type
+    if (defined(invoker.product_type)) {
+      _product_type = invoker.product_type
+    }
+
+    _app_bundle_extension = ".app"
+    _bundle_extension = _app_bundle_extension
+    if (defined(invoker.bundle_extension)) {
+      _bundle_extension = invoker.bundle_extension
+    }
+
+    # Only write PkgInfo for real application, not application extension (they
+    # have the same product type but a different extension).
+    _write_pkg_info = _product_type == _app_product_type &&
+                      _bundle_extension == _app_bundle_extension
+
+    if (_write_pkg_info) {
       _create_pkg_info = target_name + "_pkg_info"
       action(_create_pkg_info) {
         forward_variables_from(invoker, [ "testonly" ])
@@ -887,7 +875,7 @@ template("ios_app_bundle") {
         if (!defined(bundle_deps)) {
           bundle_deps = []
         }
-        if (_is_app_framework) {
+        if (_write_pkg_info) {
           bundle_deps += [ ":$_bundle_data_pkg_info" ]
         }
         bundle_deps += _variant.bundle_deps
@@ -962,6 +950,7 @@ template("ios_appex_bundle") {
                              "bundle_extension",
                              "product_type",
                            ])
+    bundle_extension = ".appex"
     product_type = "com.apple.product-type.app-extension"
 
     # Add linker flags required for an application extension (determined by