Add an IPC method for Blink to call RapporService::RecordSample()

content/public/test/mock_render_thread.h

Index: content/public/test/mock_render_thread.h
diff --git a/content/public/test/mock_render_thread.h b/content/public/test/mock_render_thread.h
index 95d7be8887db880b11f35e4d82fe786f556b5d8d..3033aad5f2bd2c53cff71feeb0faff190a301590 100644
--- a/content/public/test/mock_render_thread.h
+++ b/content/public/test/mock_render_thread.h
@@ -57,6 +57,9 @@ class MockRenderThread : public RenderThread {
   void EnsureWebKitInitialized() override;
   void RecordAction(const base::UserMetricsAction& action) override;
   void RecordComputedAction(const std::string& action) override;
+  void RecordRappor(
+      const std::string& metric,
+      const std::string& sample) override;
   scoped_ptr<base::SharedMemory> HostAllocateSharedMemoryBuffer(
       size_t buffer_size) override;
   cc::SharedBitmapManager* GetSharedBitmapManager() override;