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

content/browser/tab_contents/tab_contents_unittest.cc

Index: content/browser/tab_contents/tab_contents_unittest.cc
diff --git a/content/browser/tab_contents/tab_contents_unittest.cc b/content/browser/tab_contents/tab_contents_unittest.cc
index a00c3f1e63c0023d6ed5d921c98dc30092e44e40..374b467fefb406ab42131abb2f7805031836ea86 100644
--- a/content/browser/tab_contents/tab_contents_unittest.cc
+++ b/content/browser/tab_contents/tab_contents_unittest.cc
@@ -281,14 +281,15 @@ class TabContentsTest : public RenderViewHostImplTestHarness {
 
     old_client_ = content::GetContentClient();
     old_browser_client_ = content::GetContentClient()->browser();
-    content::SetContentClient(&client_);
+    old_user_agent_ = content::GetUserAgent();
+    content::Initialize(&client_, "TabContentsTest");
     content::GetContentClient()->set_browser(&browser_client_);
     RenderViewHostImplTestHarness::SetUp();
   }
 
   virtual void TearDown() {
     content::GetContentClient()->set_browser(old_browser_client_);
-    content::SetContentClient(old_client_);
+    content::Initialize(old_client_, old_user_agent_);
     RenderViewHostImplTestHarness::TearDown();
   }
 
@@ -298,6 +299,7 @@ class TabContentsTest : public RenderViewHostImplTestHarness {
   content::TestBrowserThread ui_thread_;
   content::ContentClient* old_client_;
   content::ContentBrowserClient* old_browser_client_;
+  std::string old_user_agent_;
 };
 
 }  // namespace