CrOS: Add print statements to help debug BrowserProcessImpl::Unpin crash.

chrome/browser/lifetime/keep_alive_registry.h

Index: chrome/browser/lifetime/keep_alive_registry.h
diff --git a/chrome/browser/lifetime/keep_alive_registry.h b/chrome/browser/lifetime/keep_alive_registry.h
index d8a7e4f0f95ac4df327ed72b896e86b45d346c3e..db3c61b1b6ead005bb4b5fecdef859383d40f24d 100644
--- a/chrome/browser/lifetime/keep_alive_registry.h
+++ b/chrome/browser/lifetime/keep_alive_registry.h
@@ -40,6 +40,11 @@ class KeepAliveRegistry {
   // provided |origins| were not registered.
   bool WouldRestartWithout(const std::vector<KeepAliveOrigin>& origins) const;
 
+  // TODO(sammiequon): This is used to help debug the crash in crbug.com/660962.
+  // Remove this when the crash is fixed or if verified to not be related to
+  // this.
+  std::string ToString() const;

[sky, 2017/03/22 03:56:16]

How about naming this more specifically, possibly ToDebugString()?

+
  private:
   friend struct base::DefaultSingletonTraits<KeepAliveRegistry>;
   // Friend to be able to use Register/Unregister