Move --user-agent overriding logic from chrome into content.

content/browser/tab_contents/render_view_host_manager_unittest.cc

Index: content/browser/tab_contents/render_view_host_manager_unittest.cc
diff --git a/content/browser/tab_contents/render_view_host_manager_unittest.cc b/content/browser/tab_contents/render_view_host_manager_unittest.cc
index 66027fd9a1961eb3ef4e6232569552d6ec78b6e6..2dba56d7e7fdaa584f5adba065751ec013eb3961 100644
--- a/content/browser/tab_contents/render_view_host_manager_unittest.cc
+++ b/content/browser/tab_contents/render_view_host_manager_unittest.cc
@@ -136,7 +136,8 @@ class RenderViewHostManagerTest
     RenderViewHostImplTestHarness::SetUp();
     old_client_ = content::GetContentClient();
     old_browser_client_ = content::GetContentClient()->browser();
-    content::SetContentClient(&client_);
+    old_user_agent_ = content::GetUserAgent(GURL());
+    content::Initialize(&client_, "RenderViewHostManagerTest");
     content::GetContentClient()->set_browser(&browser_client_);
     url_util::AddStandardScheme(chrome::kChromeUIScheme);
   }
@@ -144,7 +145,7 @@ class RenderViewHostManagerTest
   virtual void TearDown() OVERRIDE {
     RenderViewHostImplTestHarness::TearDown();
     content::GetContentClient()->set_browser(old_browser_client_);
-    content::SetContentClient(old_client_);
+    content::Initialize(old_client_, old_user_agent_);
   }
 
   void set_should_create_webui(bool should_create_webui) {
@@ -186,6 +187,7 @@ class RenderViewHostManagerTest
   RenderViewHostManagerTestBrowserClient browser_client_;
   content::ContentClient* old_client_;
   content::ContentBrowserClient* old_browser_client_;
+  std::string old_user_agent_;
 };
 
 // Tests that when you navigate from the New TabPage to another page, and