diff --git a/tools/gn/xcode_object.cc b/tools/gn/xcode_object.cc
index eeae7e4..9854095 100644
--- a/tools/gn/xcode_object.cc
+++ b/tools/gn/xcode_object.cc
@@ -487,6 +487,19 @@
   DCHECK(!source_path.empty());
   std::string::size_type sep = navigator_path.find("/");
   if (sep == std::string::npos) {
+    // Prevent same file reference being created and added multiple times.
+    for (const auto& child : children_) {
+      if (child->Class() != PBXFileReferenceClass)
+        continue;
+
+      PBXFileReference* child_as_file_reference =
+          static_cast<PBXFileReference*>(child.get());
+      if (child_as_file_reference->Name() == navigator_path &&
+          child_as_file_reference->path() == source_path) {
+        return child_as_file_reference;
+      }
+    }
+
     children_.push_back(base::MakeUnique<PBXFileReference>(
         navigator_path, source_path, std::string()));
     return static_cast<PBXFileReference*>(children_.back().get());
@@ -675,12 +688,13 @@
   target_for_indexing_ = static_cast<PBXNativeTarget*>(targets_.back().get());
 }
 
-void PBXProject::AddNativeTarget(const std::string& name,
-                                 const std::string& type,
-                                 const std::string& output_name,
-                                 const std::string& output_type,
-                                 const std::string& shell_script,
-                                 const PBXAttributes& extra_attributes) {
+PBXNativeTarget* PBXProject::AddNativeTarget(
+    const std::string& name,
+    const std::string& type,
+    const std::string& output_name,
+    const std::string& output_type,
+    const std::string& shell_script,
+    const PBXAttributes& extra_attributes) {
   base::StringPiece ext = FindExtension(&output_name);
   PBXFileReference* product = static_cast<PBXFileReference*>(
       products_->AddChild(base::MakeUnique<PBXFileReference>(
@@ -700,6 +714,7 @@
   targets_.push_back(base::MakeUnique<PBXNativeTarget>(
       name, shell_script, config_name_, attributes, output_type, product_name,
       product));
+  return static_cast<PBXNativeTarget*>(targets_.back().get());
 }
 
 void PBXProject::SetProjectDirPath(const std::string& project_dir_path) {
diff --git a/tools/gn/xcode_object.h b/tools/gn/xcode_object.h
index 3454e85..a6ab32a 100644
--- a/tools/gn/xcode_object.h
+++ b/tools/gn/xcode_object.h
@@ -190,6 +190,8 @@
   std::string Name() const override;
   void Print(std::ostream& out, unsigned indent) const override;
 
+  const std::string& path() const { return path_; }
+
  private:
   std::string name_;
   std::string path_;
@@ -293,12 +295,13 @@
   void AddAggregateTarget(const std::string& name,
                           const std::string& shell_script);
   void AddIndexingTarget();
-  void AddNativeTarget(const std::string& name,
-                       const std::string& type,
-                       const std::string& output_name,
-                       const std::string& output_type,
-                       const std::string& shell_script,
-                       const PBXAttributes& extra_attributes = PBXAttributes());
+  PBXNativeTarget* AddNativeTarget(
+      const std::string& name,
+      const std::string& type,
+      const std::string& output_name,
+      const std::string& output_type,
+      const std::string& shell_script,
+      const PBXAttributes& extra_attributes = PBXAttributes());
 
   void SetProjectDirPath(const std::string& project_dir_path);
   void SetProjectRoot(const std::string& project_root);
diff --git a/tools/gn/xcode_writer.cc b/tools/gn/xcode_writer.cc
index 5030b5a..242f0b0 100644
--- a/tools/gn/xcode_writer.cc
+++ b/tools/gn/xcode_writer.cc
@@ -32,10 +32,16 @@
 namespace {
 
 using TargetToFileList = std::unordered_map<const Target*, Target::FileList>;
+using TargetToNativeTarget =
+    std::unordered_map<const Target*, PBXNativeTarget*>;
+using FileToTargets = std::map<SourceFile,
+                               std::vector<const Target*>,
+                               bool (*)(const SourceFile&, const SourceFile&)>;
 
 const char kEarlGreyFileNameIdentifier[] = "egtest.mm";
 const char kXCTestFileNameIdentifier[] = "xctest.mm";
 const char kXCTestModuleTargetNamePostfix[] = "_module";
+const char kXCTestFileReferenceFolder[] = "xctests/";
 
 struct SafeEnvironmentVariableInfo {
   const char* name;
@@ -47,6 +53,15 @@
     {"USER", true}, {"TMPDIR", false},
 };
 
+bool CompareSourceFiles(const SourceFile& lhs, const SourceFile& rhs) {
+  if (lhs.GetName() < rhs.GetName())
+    return true;
+  else if (lhs.GetName() > rhs.GetName())
+    return false;
+  else
+    return lhs.value() < rhs.value();
+}
+
 XcodeWriter::TargetOsType GetTargetOs(const Args& args) {
   const Value* target_os_value = args.GetArgOverride(variables::kTargetOs);
   if (target_os_value) {
@@ -193,6 +208,31 @@
   }
 }
 
+// Maps each xctest file to a list of xctest application targets that contains
+// the file.
+void MapXCTestFileToApplicationTargets(
+    const std::vector<const Target*>& xctest_application_targets,
+    const std::vector<Target::FileList>& xctest_file_lists,
+    FileToTargets* xctest_file_to_application_targets) {
+  DCHECK_EQ(xctest_application_targets.size(), xctest_file_lists.size());
+
+  for (size_t i = 0; i < xctest_application_targets.size(); ++i) {
+    const Target* xctest_application_target = xctest_application_targets[i];
+    DCHECK(IsApplicationTarget(xctest_application_target));
+
+    for (const SourceFile& source : xctest_file_lists[i]) {
+      auto iter = xctest_file_to_application_targets->find(source);
+      if (iter == xctest_file_to_application_targets->end()) {
+        iter =
+            xctest_file_to_application_targets
+                ->insert(std::make_pair(source, std::vector<const Target*>()))
+                .first;
+      }
+      iter->second.push_back(xctest_application_target);
+    }
+  }
+}
+
 class CollectPBXObjectsPerClassHelper : public PBXObjectVisitor {
  public:
   CollectPBXObjectsPerClassHelper() {}
@@ -417,6 +457,8 @@
   main_project->AddAggregateTarget(
       "All", GetBuildScript(root_target, ninja_extra_args, env.get()));
 
+  TargetToNativeTarget xctest_application_to_module_native_target;
+
   for (const Target* target : targets) {
     switch (target->output_type()) {
       case Target::EXECUTABLE:
@@ -447,7 +489,7 @@
           extra_attributes["DEBUG_INFORMATION_FORMAT"] = "dwarf";
         }
 
-        main_project->AddNativeTarget(
+        PBXNativeTarget* native_target = main_project->AddNativeTarget(
             target->label().name(), std::string(),
             RebasePath(target->bundle_data()
                            .GetBundleRootDirOutput(target->settings())
@@ -456,6 +498,17 @@
             target->bundle_data().product_type(),
             GetBuildScript(target->label().name(), ninja_extra_args, env.get()),
             extra_attributes);
+
+        if (!IsXCTestModuleTarget(target))
+          continue;
+
+        // Populate |xctest_application_to_module_native_target| for XCTest
+        // module targets.
+        const Target* application_target =
+            FindXCTestApplicationTarget(target, xctest_application_targets);
+        xctest_application_to_module_native_target.insert(
+            std::make_pair(application_target, native_target));
+
         break;
       }
 
@@ -464,6 +517,34 @@
     }
   }
 
+  FileToTargets xctest_file_to_application_targets(CompareSourceFiles);
+  MapXCTestFileToApplicationTargets(xctest_application_targets,
+                                    xctest_file_lists,
+                                    &xctest_file_to_application_targets);
+
+  // Add xctest files to the "Compiler Sources" of corresponding xctest native
+  // targets.
+  SourceDir source_dir("//");
+  for (const auto& item : xctest_file_to_application_targets) {
+    const SourceFile& source = item.first;
+    for (const Target* xctest_application_target : item.second) {
+      std::string navigator_path =
+          kXCTestFileReferenceFolder + source.GetName();
+      std::string source_path = RebasePath(source.value(), source_dir,
+                                           build_settings->root_path_utf8());
+      PBXNativeTarget* xctest_module_native_target =
+          xctest_application_to_module_native_target[xctest_application_target];
+
+      // Test files need to be known to Xcode for proper indexing and for
+      // discovery of tests function for XCTest, but the compilation is done
+      // via ninja and thus must prevent Xcode from compiling the files by
+      // adding '-help' as per file compiler flag.
+      main_project->AddSourceFile(navigator_path, source_path,
+                                  CompilerFlags::HELP,
+                                  xctest_module_native_target);
+    }
+  }
+
   projects_.push_back(std::move(main_project));
 }