Add FilePath to base namespace.

content/public/test/browser_test_base.h

Index: content/public/test/browser_test_base.h
diff --git a/content/public/test/browser_test_base.h b/content/public/test/browser_test_base.h
index 121b429469a236d1ef0a7a9156dbd5e8eb0cdd93..026bf321f91001ad7f59efd46be795336983a1d9 100644
--- a/content/public/test/browser_test_base.h
+++ b/content/public/test/browser_test_base.h
@@ -10,7 +10,10 @@
 #include "net/test/test_server.h"
 
 class CommandLine;
+
+namespace base {
 class FilePath;
+}
 
 namespace content {
 
@@ -77,7 +80,7 @@ class BrowserTestBase : public testing::Test {
   // this.
   // |test_server_base| is the path, relative to src, to give to the test HTTP
   // server.
-  void CreateTestServer(const FilePath& test_server_base);
+  void CreateTestServer(const base::FilePath& test_server_base);
 
  private:
   void ProxyRunTestOnMainThreadLoop();