[Chromecast] Remove CastContentBrowserClient::PreCreateThreads

Moved to CastBrowserMainParts, per the bug.

Bug: internal b/27811461
Test: none
Change-Id: Ic3fd8f7ed51473e8a61caff62c5caa762af03b84
Reviewed-on: https://chromium-review.googlesource.com/811286Reviewed-by: Sergey Volk <servolk@chromium.org>
Commit-Queue: Luke Halliwell <halliwell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522320}

chromecast/browser/BUILD.gn

@@ -70,6 +70,7 @@ cast_source_set("browser") {
 
   if (chromecast_branding == "public") {
     sources += [
+      "cast_browser_main_parts_simple.cc",
       "cast_content_browser_client_simple.cc",
       "cast_network_delegate_simple.cc",
       "pref_service_helper_simple.cc",

chromecast/browser/cast_browser_main_parts.cc

@@ -442,9 +442,6 @@ int CastBrowserMainParts::PreCreateThreads() {
       command_line->GetSwitchValueASCII(switches::kEnableFeatures),
       command_line->GetSwitchValueASCII(switches::kDisableFeatures));
 
-  // Hook for internal code
-  cast_browser_process_->browser_client()->PreCreateThreads();
-
 #if defined(USE_AURA)
   cast_browser_process_->SetCastScreen(base::WrapUnique(new CastScreen()));
   DCHECK(!display::Screen::GetScreen());

chromecast/browser/cast_browser_main_parts.h

@@ -42,6 +42,12 @@ class URLRequestContextFactory;
 
 class CastBrowserMainParts : public content::BrowserMainParts {
  public:
+  // Creates an implementation of CastBrowserMainParts. Platform should
+  // link in an implementation as needed.
+  static std::unique_ptr<CastBrowserMainParts> Create(
+      const content::MainFunctionParams& parameters,
+      URLRequestContextFactory* url_request_context_factory);
+
   // This class does not take ownership of |url_request_content_factory|.
   CastBrowserMainParts(const content::MainFunctionParams& parameters,
                        URLRequestContextFactory* url_request_context_factory);

chromecast/browser/cast_browser_main_parts_simple.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chromecast/browser/cast_browser_main_parts.h"
+
+namespace chromecast {
+namespace shell {
+
+// static
+std::unique_ptr<CastBrowserMainParts> CastBrowserMainParts::Create(
+    const content::MainFunctionParams& parameters,
+    URLRequestContextFactory* url_request_context_factory) {
+  return std::make_unique<CastBrowserMainParts>(parameters,
+                                                url_request_context_factory);
+}
+
+}  // namespace shell
+}  // namespace chromecast

chromecast/browser/cast_content_browser_client.cc

@@ -182,8 +182,6 @@ void CastContentBrowserClient::AppendExtraCommandLineSwitches(
 #endif  // defined(USE_AURA)
 }
 
-void CastContentBrowserClient::PreCreateThreads() {}
-
 std::unique_ptr<CastService> CastContentBrowserClient::CreateCastService(
     content::BrowserContext* browser_context,
     PrefService* pref_service,
@@ -282,10 +280,14 @@ bool CastContentBrowserClient::EnableRemoteDebuggingImmediately() {
 content::BrowserMainParts* CastContentBrowserClient::CreateBrowserMainParts(
     const content::MainFunctionParams& parameters) {
   DCHECK(!cast_browser_main_parts_);
-  cast_browser_main_parts_ =
-      new CastBrowserMainParts(parameters, url_request_context_factory_.get());
+  auto main_parts = CastBrowserMainParts::Create(
+      parameters, url_request_context_factory_.get());
+  cast_browser_main_parts_ = main_parts.get();
   CastBrowserProcess::GetInstance()->SetCastContentBrowserClient(this);
-  return cast_browser_main_parts_;
+
+  // TODO(halliwell): would like to change CreateBrowserMainParts to return
+  // unique_ptr, then we don't have to release.
+  return main_parts.release();
 }
 
 void CastContentBrowserClient::RenderProcessWillLaunch(

chromecast/browser/cast_content_browser_client.h

@@ -67,9 +67,6 @@ class CastContentBrowserClient : public content::ContentBrowserClient {
   // Appends extra command line arguments before launching a new process.
   virtual void AppendExtraCommandLineSwitches(base::CommandLine* command_line);
 
-  // Hook for code to run before browser threads created.
-  virtual void PreCreateThreads();
-
   // Creates and returns the CastService instance for the current process.
   // Note: |request_context_getter| might be different than the main request
   // getter accessible via CastBrowserProcess.