- Factor platform-specific code out of CefBrowserHostImpl (issue #1749).

- Introduce native/ and osr/ folders for native (non-platform-agnostic) and
    osr (windowless) code respectively.
  - Introduce CefBrowserPlatformDelegate for abstracting platform-specific
    implementations of browser host functionality.
  - Move dialog and menu code to separate manager and platform-specific runner
    implementations exposed via CefBrowserPlatformDelegate.
  - Standardize focus-handling behavior between windowed and windowless
    implementations. CefFocusHandler::OnSetFocus() will now also be called for
    osr focus changes.
- Support multiple simultaneous popups (issue #1289).

libcef/browser/extensions/browser_extensions_util.cc

@@ -4,7 +4,7 @@
 
 #include "libcef/browser/extensions/browser_extensions_util.h"
 
-#include "libcef/browser/content_browser_client.h"
+#include "libcef/browser/browser_info_manager.h"
 #include "libcef/browser/thread_util.h"
 #include "libcef/common/extensions/extensions_util.h"
 
@@ -72,7 +72,7 @@ CefRefPtr<CefBrowserHostImpl> GetOwnerBrowserForView(int render_process_id,
   } else {
     // Use the thread-safe approach.
     scoped_refptr<CefBrowserInfo> info =
-        CefContentBrowserClient::Get()->GetBrowserInfoForView(
+        CefBrowserInfoManager::GetInstance()->GetBrowserInfoForView(
             render_process_id, render_routing_id, is_guest_view);
     if (info.get()) {
       CefRefPtr<CefBrowserHostImpl> browser = info->browser();