Make WebSpellCheckClient aware of leak detection

third_party/WebKit/Source/web/tests/WebFrameTest.cpp

Index: third_party/WebKit/Source/web/tests/WebFrameTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/WebFrameTest.cpp b/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
index a881cd8ec2ae8b71dc132bd296ab5bd937ac4212..ef89d08fcb3a3cfc6c5bf8b52c329e79ff03986e 100644
--- a/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
+++ b/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
@@ -5266,6 +5266,14 @@ public:
         m_completion = completion;
     }
 
+    void prepareForLeakDetection() override
+    {
+        if (!m_completion)
+            return;
+        m_completion->didCancelCheckingText();
+        m_completion = nullptr;
+    }
+
     void kickNoResults()
     {
         kick(-1, -1, WebTextDecorationTypeSpelling);