mac: Let Carbon plugin stuff buid with the 10.7 SDK

content/plugin/plugin_carbon_interpose_mac.cc

Index: content/plugin/plugin_carbon_interpose_mac.cc
diff --git a/content/plugin/plugin_carbon_interpose_mac.cc b/content/plugin/plugin_carbon_interpose_mac.cc
index 20a7d543aee12ee364f7b2b74bdb2832d10d89cf..7dd4f0173b9ed944d0d7048f29a5abf8c366ed05 100644
--- a/content/plugin/plugin_carbon_interpose_mac.cc
+++ b/content/plugin/plugin_carbon_interpose_mac.cc
@@ -12,6 +12,17 @@
 
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 
+#if defined(MAC_OS_X_VERSION_10_7) && \
+    MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7
+// QuickdrawAPI.h is no longer included in the 10.7 SDK, but the symbols are
+// still exported by QD.framework (a subframework of ApplicationServices).
+// http://developer.apple.com/legacy/mac/library/documentation/Carbon/reference/QuickDraw_Ref/QuickDraw_Ref.pdf
+extern "C" {
+Boolean PtInRect(Point pt, const Rect* r);
+void SetCursor(const Cursor* crsr);
+}
+#endif  // 10.7+ SDK
+
 // Returns true if the given window is modal.
 static bool IsModalWindow(WindowRef window) {
   WindowModality modality = kWindowModalityNone;