[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/+/2201096Reviewed-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}

build/config/ios/rules.gni

@@ -512,13 +512,10 @@ 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 generally
-#       not be overridden.
+#       default to "com.apple.product-type.application". Should only be
+#       overriden when building application extension.
 #
 #   enable_code_signing
 #       (optional) boolean, control whether code signing is enabled or not,
@@ -633,6 +630,25 @@ 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,
                            "*",
@@ -682,6 +698,18 @@ 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)" ]
 
@@ -792,24 +820,8 @@ template("ios_app_bundle") {
       }
     }
 
-    _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) {
+    # Only write PkgInfo for real application, not application extension.
+    if (_is_app_framework) {
       _create_pkg_info = target_name + "_pkg_info"
       action(_create_pkg_info) {
         forward_variables_from(invoker, [ "testonly" ])
@@ -875,7 +887,7 @@ template("ios_app_bundle") {
         if (!defined(bundle_deps)) {
           bundle_deps = []
         }
-        if (_write_pkg_info) {
+        if (_is_app_framework) {
           bundle_deps += [ ":$_bundle_data_pkg_info" ]
         }
         bundle_deps += _variant.bundle_deps
@@ -950,7 +962,6 @@ 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