Reuse PrintContext to excessively triggering matchMedia('print') listeners.

webkit/glue/webkit_glue.cc

Index: webkit/glue/webkit_glue.cc
diff --git a/webkit/glue/webkit_glue.cc b/webkit/glue/webkit_glue.cc
index 1d8930577160eccdc754a36141b5232720b21494..694dce64bc68f76b9fe8ac0c4179e067d110bc6e 100644
--- a/webkit/glue/webkit_glue.cc
+++ b/webkit/glue/webkit_glue.cc
@@ -154,7 +154,8 @@ int NumberOfPages(WebFrame* web_frame,
                   float page_height_in_pixels) {
   WebSize size(static_cast<int>(page_width_in_pixels),
                static_cast<int>(page_height_in_pixels));
-  int number_of_pages = web_frame->printBegin(size);
+  web_frame->printBegin();
+  int number_of_pages = web_frame->setPageSizeResolution(size);
   web_frame->printEnd();
   return number_of_pages;
 }