Support sharing of ContentMain and BrowserMain code with embedded use cases.

content/shell/shell_browser_main.cc

Index: content/shell/shell_browser_main.cc
===================================================================
--- content/shell/shell_browser_main.cc	(revision 117304)
+++ content/shell/shell_browser_main.cc	(working copy)
@@ -16,6 +16,7 @@
 #include "content/shell/shell.h"
 #include "content/shell/shell_browser_context.h"
 #include "content/shell/shell_content_browser_client.h"
+#include "content/shell/shell_main_delegate.h"
 #include "net/base/net_module.h"
 #include "ui/base/clipboard/clipboard.h"
 
@@ -31,8 +32,10 @@
 }
 
 ShellBrowserMainParts::ShellBrowserMainParts(
+    ShellMainDelegate* delegate,
     const content::MainFunctionParams& parameters)
-    : BrowserMainParts() {
+    : BrowserMainParts(),
+      delegate_(delegate) {
   ShellContentBrowserClient* shell_browser_client =
       static_cast<ShellContentBrowserClient*>(
           content::GetContentClient()->browser());
@@ -42,6 +45,14 @@
 ShellBrowserMainParts::~ShellBrowserMainParts() {
 }
 
+MessageLoop* ShellBrowserMainParts::GetMainMessageLoop() {
+#if defined(TEST_EMBEDDED_MESSAGE_LOOP)
+  return delegate_->CreateBrowserMessageLoop();
+#else
+  return NULL;
+#endif
+}
+
 void ShellBrowserMainParts::PreMainMessageLoopRun() {
   browser_context_.reset(new ShellBrowserContext(this));