ThreadRestrictions: disallow blocking IO on the UI thread

chrome/browser/browser_main.cc

Index: chrome/browser/browser_main.cc
diff --git a/chrome/browser/browser_main.cc b/chrome/browser/browser_main.cc
index 92a3b68f85a3eeeff3bbf97376ec2eaf2e13a36b..dd1217d95cf930ac26440f0d85408224799a1732 100644
--- a/chrome/browser/browser_main.cc
+++ b/chrome/browser/browser_main.cc
@@ -27,6 +27,7 @@
 #include "base/string_split.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
+#include "base/thread_restrictions.h"
 #include "base/time.h"
 #include "base/trace_event.h"
 #include "base/utf_string_conversions.h"
@@ -478,6 +479,14 @@ void HandleTestParameters(const CommandLine& command_line) {
 void RunUIMessageLoop(BrowserProcess* browser_process) {
   TRACE_EVENT_BEGIN("BrowserMain:MESSAGE_LOOP", 0, "");
 
+#if defined(OS_LINUX)
+  // If the UI thread blocks, the whole UI is unresponsive.
+  // Do not allow disk IO from the UI thread.
+  // TODO(evanm): turn this on for all platforms.
+  //   http://code.google.com/p/chromium/issues/detail?id=60211
+  base::ThreadRestrictions::SetIOAllowed(false);
+#endif
+
 #if defined(TOOLKIT_VIEWS)
   views::AcceleratorHandler accelerator_handler;
   MessageLoopForUI::current()->Run(&accelerator_handler);