TestingPlatformSupport: register Platform instance correctly

third_party/WebKit/Source/platform/testing/TestingPlatformSupport.h

Index: third_party/WebKit/Source/platform/testing/TestingPlatformSupport.h
diff --git a/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.h b/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.h
index 159c0febae33681c850788625010da4a68eee369..49e60e5221568eb72a96605ca31bf8654e5b7ee7 100644
--- a/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.h
+++ b/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.h
@@ -31,6 +31,7 @@
 #ifndef TestingPlatformSupport_h
 #define TestingPlatformSupport_h
 
+#include "base/logging.h"

[Takashi Toyoshima, 2017/01/11 08:35:19]

removed

 #include "platform/PlatformExport.h"
 #include "platform/WebTaskRunner.h"
 #include "public/platform/Platform.h"
@@ -188,6 +189,33 @@ class TestingPlatformSupportWithMockScheduler : public TestingPlatformSupport {
   std::unique_ptr<WebThread> m_thread;
 };
 
+template <class T>
+class ScopedTestingPlatformSupport {
+ public:
+  ScopedTestingPlatformSupport() : m_originalPlatform(Platform::current()) {}
+  explicit ScopedTestingPlatformSupport(T* testingPlatformSupport)

[jbroman, 2016/12/22 15:27:54]

Taking ownership by raw pointer, here and below, is something we're trying to
get rid of. Could this take std::unique_ptr instead (and have the callers use
MakeUnique)?

[Takashi Toyoshima, 2017/01/11 08:35:19]

Done.

+      : m_originalPlatform(Platform::current()) {
+    reset(testingPlatformSupport);
+  }
+  void reset(T* testingPlatformSupport) {
+    DCHECK_NE(m_testingPlatformSupport.get(), testingPlatformSupport);
+    if (testingPlatformSupport)
+      Platform::setCurrentPlatformForTesting(testingPlatformSupport);
+    m_testingPlatformSupport.reset(testingPlatformSupport);
+  }
+  ~ScopedTestingPlatformSupport() {
+    m_testingPlatformSupport.reset();
+    if (m_originalPlatform)
+      Platform::setCurrentPlatformForTesting(m_originalPlatform);
+  }
+  const T* operator->() const { return m_testingPlatformSupport.get(); }
+  T* operator->() { return m_testingPlatformSupport.get(); }
+
+ private:
+  Platform* m_originalPlatform;
+  std::unique_ptr<T> m_testingPlatformSupport;
+};
+
 class ScopedUnittestsEnvironmentSetup {
   WTF_MAKE_NONCOPYABLE(ScopedUnittestsEnvironmentSetup);
 
@@ -202,7 +230,7 @@ class ScopedUnittestsEnvironmentSetup {
   std::unique_ptr<DummyPlatform> m_platform;
   std::unique_ptr<cc_blink::WebCompositorSupportImpl> m_compositorSupport;
   TestingPlatformSupport::Config m_testingPlatformConfig;
-  std::unique_ptr<TestingPlatformSupport> m_testingPlatformSupport;
+  ScopedTestingPlatformSupport<TestingPlatformSupport> m_testingPlatformSupport;
 };
 
 }  // namespace blink