[OLD ATTEMPT, DO NOT REVIEW] mustash: Enable connections to mus from the Chrome renderer

content/browser/mojo/mojo_shell_client_host.cc

Index: content/browser/mojo/mojo_shell_client_host.cc
diff --git a/content/browser/mojo/mojo_shell_client_host.cc b/content/browser/mojo/mojo_shell_client_host.cc
index 1bc85b51f168de0d8bc05c6909e59fe1d5f3771c..a7c4dd1957811e4427e75de565d59052dbd9fe46 100644
--- a/content/browser/mojo/mojo_shell_client_host.cc
+++ b/content/browser/mojo/mojo_shell_client_host.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/thread_task_runner_handle.h"
 #include "content/browser/mojo/mojo_shell_client_host.h"
@@ -9,6 +10,7 @@
 #include "content/public/browser/render_process_host.h"
 #include "content/public/common/mojo_shell_connection.h"
 #include "ipc/ipc_sender.h"
+#include "mojo/application/public/cpp/application_connection.h"
 #include "mojo/application/public/cpp/application_impl.h"
 #include "mojo/converters/network/network_type_converters.h"
 #include "mojo/shell/application_manager.mojom.h"
@@ -103,4 +105,17 @@ std::string GetMojoApplicationInstanceURL(
   return instance_url ? instance_url->get() : std::string();
 }
 
+int GetRenderProcessIDFromConnection(mojo::ApplicationConnection* connection) {
+  // Just use the host name for finding the string to avoid checking for
+  // slashes.
+  const char kChromeRenderer[] = "chrome_renderer";
+  const std::string& url = connection->GetRemoteApplicationURL();
+  size_t pos = url.find_last_of(kChromeRenderer);
+  std::string val(url.substr(pos + 1, url.size() - pos - 2));
+  int render_process_id = 0;
+  if (!base::StringToInt(val, &render_process_id) || !render_process_id)
+    return 0;
+  return render_process_id;
+}
+
 }  // namespace content