Add 'didDispatchPingLoader' callback to FrameLoaderClient.

Source/testing/runner/TestRunner.h

Index: Source/testing/runner/TestRunner.h
diff --git a/Source/testing/runner/TestRunner.h b/Source/testing/runner/TestRunner.h
index 578134c0553695c88f84cf8298a85862ecdd8284..953b050844bd5bd510d2635d570ca09613cfe4fc 100644
--- a/Source/testing/runner/TestRunner.h
+++ b/Source/testing/runner/TestRunner.h
@@ -98,8 +98,10 @@ public:
     void setShouldDumpAsText(bool);
     void setShouldGeneratePixelResults(bool);
     void setShouldDumpFrameLoadCallbacks(bool);
+    void setShouldDumpPingLoaderCallbacks(bool);
     bool shouldDumpEditingCallbacks() const;
     bool shouldDumpFrameLoadCallbacks() const;
+    bool shouldDumpPingLoaderCallbacks() const;
     bool shouldDumpUserGestureInFrameLoadCallbacks() const;
     bool shouldDumpTitleChanges() const;
     bool shouldDumpIconChanges() const;
@@ -340,6 +342,11 @@ private:
     void dumpFrameLoadCallbacks(const CppArgumentList&, CppVariant*);
 
     // This function sets a flag that tells the test_shell to print a line of
+    // descriptive text for each PingLoader dispatch. It takes no arguments, and
+    // ignores any that may be present.
+    void dumpPingLoaderCallbacks(const CppArgumentList&, CppVariant*);
+
+    // This function sets a flag that tells the test_shell to print a line of
     // user gesture status text for some frame load callbacks. It takes no
     // arguments, and ignores any that may be present.
     void dumpUserGestureInFrameLoadCallbacks(const CppArgumentList&, CppVariant*);
@@ -608,6 +615,10 @@ private:
     // load callback.
     bool m_dumpFrameLoadCallbacks;
 
+    // If true, the test_shell will output a descriptive line for each
+    // PingLoader dispatched.
+    bool m_dumpPingLoaderCallbacks;
+
     // If true, the test_shell will output a line of the user gesture status
     // text for some frame load callbacks.
     bool m_dumpUserGestureInFrameLoadCallbacks;