PrintPreviewPdfGeneratedBrowserTest properly listens to messages and exits correctly.

chrome/browser/printing/print_preview_pdf_generated_browsertest.cc

Index: chrome/browser/printing/print_preview_pdf_generated_browsertest.cc
diff --git a/chrome/browser/printing/print_preview_pdf_generated_browsertest.cc b/chrome/browser/printing/print_preview_pdf_generated_browsertest.cc
index f8dd016d8476c5926f51517be79752c56119d139..38664dacf5e62429b2e85b3e67332d40e5c46200 100644
--- a/chrome/browser/printing/print_preview_pdf_generated_browsertest.cc
+++ b/chrome/browser/printing/print_preview_pdf_generated_browsertest.cc
@@ -652,15 +652,10 @@ IN_PROC_BROWSER_TEST_F(PrintPreviewPdfGeneratedBrowserTest,
   // browsertest must be run with '--single_process' not '--single-process.'
   while (true) {
     std::string input;
-    std::getline(std::cin, input);

[ivandavid, 2014/07/23 03:33:57]

The error would occur after at least 1 iteration of the loop starting at 653.
The problem was that |input| would be empty,  yet |std::cin.eof()| would
evaluate to false, causing the loop to exit when it shouldn't have. To prevent
this, the loop exits when |input| is empty and just keeps clearing the state of
|std::cin| since eventually the input will be correct. |input| is guaranteed to
either be empty or have the correct input due to how the layout test framework
prints everything so this works.

-    if (input.empty()) {
-      while (std::cin.eof()) {
+    while (input.empty()) {
+      if (std::cin.eof())
         std::cin.clear();
-        std::getline(std::cin, input);
-        if (!input.empty()) {
-          break;
-        }
-      }
+      std::getline(std::cin, input);
     }
 
     base::FilePath::StringType file_extension = FILE_PATH_LITERAL(".pdf");