Use unique URLs rather than qualifiers to uniquify RenderProcesses.

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 f58065b8520714c0b9095e78f8f3bb7272c685af..e3f962f262c859a067c9bce529bda4f9b90223b6 100644
--- a/content/browser/mojo/mojo_shell_client_host.cc
+++ b/content/browser/mojo/mojo_shell_client_host.cc
@@ -2,9 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/strings/stringprintf.h"
 #include "base/thread_task_runner_handle.h"
 #include "content/browser/mojo/mojo_shell_client_host.h"
 #include "content/common/mojo/mojo_messages.h"
+#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_impl.h"
@@ -16,6 +18,9 @@
 
 namespace content {
 namespace {
+
+const char kMojoShellInstanceURL[] = "mojo_shell_instance_url";
+
 void DidCreateChannel(mojo::embedder::ChannelInfo* info) {}
 
 base::PlatformFile PlatformFileFromScopedPlatformHandle(
@@ -27,11 +32,30 @@ base::PlatformFile PlatformFileFromScopedPlatformHandle(
 #endif
 }
 
+class InstanceURL : public base::SupportsUserData::Data {
+ public:
+  InstanceURL(const std::string& instance_url) : instance_url_(instance_url) {}
+  ~InstanceURL() override {}
+
+  std::string get() const { return instance_url_; }
+
+ private:
+  std::string instance_url_;
+
+  DISALLOW_COPY_AND_ASSIGN(InstanceURL);
+};
+
+void SetMojoApplicationInstanceURL(RenderProcessHost* render_process_host,
+                                   const std::string& instance_url) {
+  render_process_host->SetUserData(kMojoShellInstanceURL,
+                                   new InstanceURL(instance_url));
+}
+
 }  // namespace
 
 void RegisterChildWithExternalShell(int child_process_id,
                                     base::ProcessHandle process_handle,
-                                    IPC::Sender* sender) {
+                                    RenderProcessHost* render_process_host) {
   // Some process types get created before the main message loop.
   if (!MojoShellConnection::Get())
     return;
@@ -57,16 +81,27 @@ void RegisterChildWithExternalShell(int child_process_id,
   //             specification is best determined (not here, this is a common
   //             chokepoint for all process types) and how to wire it through.
   //             http://crbug.com/555393
+  std::string url =
+      base::StringPrintf("exe:chrome_renderer%d", child_process_id);
   application_manager->CreateInstanceForHandle(
-      mojo::ScopedHandle(mojo::Handle(handle.release().value())),
-      "exe:chrome_renderer",  // See above about how this string is meaningless.
-      base::IntToString(child_process_id));
+      mojo::ScopedHandle(mojo::Handle(handle.release().value())), url);
 
   // Send the other end to the child via Chrome IPC.
   base::PlatformFile client_file = PlatformFileFromScopedPlatformHandle(
       platform_channel_pair.PassClientHandle());
-  sender->Send(new MojoMsg_BindExternalMojoShellHandle(
+  render_process_host->Send(new MojoMsg_BindExternalMojoShellHandle(
       IPC::GetFileHandleForProcess(client_file, process_handle, true)));
+
+  // Store the URL on the RPH so client code can access it later via
+  // GetMojoApplicationInstanceURL().
+  SetMojoApplicationInstanceURL(render_process_host, url);
+}
+
+std::string GetMojoApplicationInstanceURL(
+    RenderProcessHost* render_process_host) {
+  InstanceURL* instance_url = static_cast<InstanceURL*>(
+      render_process_host->GetUserData(kMojoShellInstanceURL));
+  return instance_url ? instance_url->get() : std::string();
 }
 
 }  // namespace content