Supports building gtest as a DLL (by Vlad Losev).

include/gtest/gtest-spi.h

@@ -48,7 +48,7 @@ namespace testing {
 // generated in the same thread that created this object or it can intercept
 // all generated failures. The scope of this mock object can be controlled with
 // the second argument to the two arguments constructor.
-class ScopedFakeTestPartResultReporter
+class GTEST_API_ ScopedFakeTestPartResultReporter
     : public TestPartResultReporterInterface {
  public:
   // The two possible mocking modes of this object.
@@ -93,7 +93,7 @@ namespace internal {
 // TestPartResultArray contains exactly one failure that has the given
 // type and contains the given substring.  If that's not the case, a
 // non-fatal failure will be generated.
-class SingleFailureChecker {
+class GTEST_API_ SingleFailureChecker {
  public:
   // The constructor remembers the arguments.
   SingleFailureChecker(const TestPartResultArray* results,