Make GTK and Aura parts orthogonal to OS parts

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 27df9071ae3bbe02233e5cbee84896bb59a5a99c..3486563494c8152f736547ed08d0f4bfc6ec785b 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -74,13 +74,19 @@
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/chrome_browser_main_chromeos.h"
-#elif defined(USE_AURA)
-#include "chrome/browser/chrome_browser_main_aura.h"
 #elif defined(OS_WIN)
 #include "chrome/browser/chrome_browser_main_win.h"
 #elif defined(OS_MACOSX)
 #include "chrome/browser/chrome_browser_main_mac.h"
 #elif defined(OS_LINUX)
+#include "chrome/browser/chrome_browser_main_linux.h"
+#endif
+
+#if defined(USE_AURA)
+#include "chrome/browser/chrome_browser_main_aura.h"
+#endif
+
+#if defined(TOOLKIT_USES_GTK)
 #include "chrome/browser/chrome_browser_main_gtk.h"
 #endif
 
@@ -101,7 +107,6 @@
 #include "chrome/browser/ui/crypto_module_password_dialog.h"
 #endif
 
-
 #if defined(USE_AURA) || defined(TOUCH_UI)
 #include "chrome/browser/renderer_host/render_widget_host_view_views.h"
 #elif defined(OS_WIN)
@@ -186,19 +191,32 @@ namespace chrome {
 
 content::BrowserMainParts* ChromeContentBrowserClient::CreateBrowserMainParts(
     const MainFunctionParams& parameters) {
+  // Construct the Main browser parts based on the OS type.
+  content::BrowserMainParts* main_parts;
+
+  // Note: OS_CHROMEOS defines OS_LINUX so handle it first.
 #if defined(OS_CHROMEOS)
-  return new ChromeBrowserMainPartsChromeos(parameters);
-#elif defined(USE_AURA)
-  return new ChromeBrowserMainPartsAura(parameters);
+  main_parts = new ChromeBrowserMainPartsChromeos(parameters);
 #elif defined(OS_WIN)
-  return new ChromeBrowserMainPartsWin(parameters);
+  main_parts = new ChromeBrowserMainPartsWin(parameters);
 #elif defined(OS_MACOSX)
-  return new ChromeBrowserMainPartsMac(parameters);
+  main_parts = new ChromeBrowserMainPartsMac(parameters);
 #elif defined(OS_LINUX)
-  return new ChromeBrowserMainPartsGtk(parameters);
+  main_parts = new ChromeBrowserMainPartsLinux(parameters);
 #else
-  return NULL;
+  NOTREACHED();
+  main_parts = new ChromeBrowserMainParts(parameters);
+#endif
+
+  // Construct additional browser parts.
+#if defined(USE_AURA)
+  main_parts->AddParts(new ChromeBrowserPartsAura());
+#endif
+#if defined(TOOLKIT_USES_GTK)
+  main_parts->AddParts(new ChromeBrowserPartsGtk());
 #endif
+
+  return main_parts;
 }
 
 RenderWidgetHostView* ChromeContentBrowserClient::CreateViewForWidget(