content: Let embedders know when MojoShellConnection is initialized.

chrome/browser/chrome_browser_main_extra_parts.h

Index: chrome/browser/chrome_browser_main_extra_parts.h
diff --git a/chrome/browser/chrome_browser_main_extra_parts.h b/chrome/browser/chrome_browser_main_extra_parts.h
index 4ab0e512d888804b6e883f19f7689b7a640b509a..a76659266ea31ae7c09c25fa895a4658b22eab1e 100644
--- a/chrome/browser/chrome_browser_main_extra_parts.h
+++ b/chrome/browser/chrome_browser_main_extra_parts.h
@@ -5,6 +5,10 @@
 #ifndef CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_H_
 #define CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_H_
 
+namespace content {
+class MojoShellConnection;
+}
+
 // Interface class for Parts owned by ChromeBrowserMainParts.
 // The default implementation for all methods is empty.
 
@@ -34,6 +38,8 @@ class ChromeBrowserMainExtraParts {
 
   // MainMessageLoopRun methods.
   virtual void PreCreateThreads() {}
+  virtual void MojoShellConnectionStarted(
+      content::MojoShellConnection* connection) {}
   virtual void PreProfileInit() {}
   virtual void PostProfileInit() {}
   virtual void PreBrowserStart() {}