Disable side-effects in filter engine tests

test/FilterEngine.cpp

 #include "BaseJsTest.h"
 
 namespace
 {
   typedef std::tr1::shared_ptr<AdblockPlus::FilterEngine> FilterEnginePtr;
 
   class FilterEngineTest : public BaseJsTest
   {
   protected:
     FilterEnginePtr filterEngine;
 
     void SetUp()
     {
       BaseJsTest::SetUp();
-      // TODO: Don't use the default ErrorCallback/WebRequest
+      jsEngine->SetFileSystem(AdblockPlus::FileSystemPtr(new LazyFileSystem));
+      jsEngine->SetWebRequest(AdblockPlus::WebRequestPtr(new LazyWebRequest));
       jsEngine->SetErrorCallback(AdblockPlus::ErrorCallbackPtr(new AdblockPlus::DefaultErrorCallback));
-      jsEngine->SetWebRequest(AdblockPlus::WebRequestPtr(new AdblockPlus::DefaultWebRequest));
       filterEngine = FilterEnginePtr(new AdblockPlus::FilterEngine(jsEngine));
     }
   };
 }
 
 TEST_F(FilterEngineTest, FilterCreation)
 {
   AdblockPlus::FilterPtr filter1 = filterEngine->GetFilter("foo");
   ASSERT_EQ(AdblockPlus::Filter::TYPE_BLOCKING, filter1->GetType());
   AdblockPlus::FilterPtr filter2 = filterEngine->GetFilter("@@foo");
@@ skipping 108 matching lines @@
   ASSERT_TRUE(match6);
   ASSERT_EQ(AdblockPlus::Filter::TYPE_BLOCKING, match6->GetType());
 
   AdblockPlus::FilterPtr match7 = filterEngine->Matches("http://example.org/tpbanner.gif", "IMAGE", "http://example.com/");
   ASSERT_TRUE(match7);
   ASSERT_EQ(AdblockPlus::Filter::TYPE_BLOCKING, match6->GetType());
 
   AdblockPlus::FilterPtr match8 = filterEngine->Matches("http://example.org/fpbanner.gif", "IMAGE", "http://example.com/");
   ASSERT_FALSE(match8);
 }