Migrate DevToolsWindow from specific to opaque frontend host messages

chrome/browser/devtools/devtools_window.cc

Index: chrome/browser/devtools/devtools_window.cc
diff --git a/chrome/browser/devtools/devtools_window.cc b/chrome/browser/devtools/devtools_window.cc
index d052d14dbf413c7d99c3a4f5ded12d9bafc4fccb..f8e1b6a769f5171fb8211b2c4d185f1b12cc4868 100644
--- a/chrome/browser/devtools/devtools_window.cc
+++ b/chrome/browser/devtools/devtools_window.cc
@@ -587,6 +587,9 @@ DevToolsWindow::DevToolsWindow(Profile* profile,
   if (inspected_rvh)
     inspected_contents_observer_.reset(new InspectedWebContentsObserver(
         content::WebContents::FromRenderViewHost(inspected_rvh)));
+
+  embedder_message_dispatcher_.reset(
+      new DevToolsEmbedderMessageDispatcher(this));
 }
 
 // static
@@ -832,6 +835,10 @@ void DevToolsWindow::WebContentsFocused(content::WebContents* contents) {
     inspected_browser->window()->WebContentsFocused(contents);
 }
 
+void DevToolsWindow::DispatchOnEmbedder(const std::string& message) {
+  embedder_message_dispatcher_->Dispatch(message);
+}
+
 void DevToolsWindow::ActivateWindow() {
   if (IsDocked() && GetInspectedBrowserWindow())
     web_contents_->GetView()->Focus();
@@ -839,10 +846,6 @@ void DevToolsWindow::ActivateWindow() {
     browser_->window()->Activate();
 }
 
-void DevToolsWindow::ChangeAttachedWindowHeight(unsigned height) {
-  NOTREACHED();  // TODO(dgozman): This is not used anymore, remove.
-}
-
 void DevToolsWindow::CloseWindow() {
   DCHECK(IsDocked());
   content::DevToolsManager::GetInstance()->ClientHostClosing(