content: Let embedders know when MojoShellConnection is initialized.

content/public/browser/browser_main_parts.h

Index: content/public/browser/browser_main_parts.h
diff --git a/content/public/browser/browser_main_parts.h b/content/public/browser/browser_main_parts.h
index 25dcaecd52382a4b387e64a2a6b2a106b179a438..ecdf0978c4d743e8be031e7ef12afd5d478d49bd 100644
--- a/content/public/browser/browser_main_parts.h
+++ b/content/public/browser/browser_main_parts.h
@@ -9,6 +9,8 @@
 
 namespace content {
 
+class MojoShellConnection;
+
 // This class contains different "stages" to be executed by |BrowserMain()|,
 // Each stage is represented by a single BrowserMainParts method, called from
 // the corresponding method in |BrowserMainLoop| (e.g., EarlyInitialization())
@@ -70,6 +72,8 @@ class CONTENT_EXPORT BrowserMainParts {
   // (or 0 if no error).
   virtual int PreCreateThreads();
 
+  virtual void MojoShellConnectionStarted(MojoShellConnection* connection) {}
+
   // This is called just before the main message loop is run.  The
   // various browser threads have all been created at this point
   virtual void PreMainMessageLoopRun() {}