Capture a report on failed browser rendez-vous.

chrome/browser/process_singleton_win.cc

Index: chrome/browser/process_singleton_win.cc
diff --git a/chrome/browser/process_singleton_win.cc b/chrome/browser/process_singleton_win.cc
index 335215680f0d1063b90260fcd4b1e7b9e39a3248..acd028744e121789a042b567edd407cda3d20160 100644
--- a/chrome/browser/process_singleton_win.cc
+++ b/chrome/browser/process_singleton_win.cc
@@ -26,14 +26,18 @@
 #include "chrome/browser/chrome_process_finder_win.h"
 #include "chrome/browser/shell_integration.h"
 #include "chrome/browser/ui/simple_message_box.h"
+#include "chrome/chrome_watcher/kasko_util.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_paths_internal.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/grit/chromium_strings.h"
+#include "chrome/installer/util/browser_distribution.h"
+#include "chrome/installer/util/util_constants.h"
 #include "chrome/installer/util/wmi.h"
 #include "content/public/common/result_codes.h"
 #include "net/base/escape.h"
+#include "third_party/kasko/kasko_features.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/win/hwnd_util.h"
 
@@ -249,6 +253,7 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcess() {
       break;
   }
 
+  // The window is hung.
   DWORD process_id = 0;
   DWORD thread_id = ::GetWindowThreadProcessId(remote_window_, &process_id);
   if (!thread_id || !process_id) {
@@ -257,7 +262,40 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcess() {
   }
   base::Process process = base::Process::Open(process_id);
 
-  // The window is hung. Scan for every window to find a visible one.
+#if BUILDFLAG(ENABLE_KASKO)

[Sigurður Ásgeirsson, 2016/03/31 19:28:49]

As we discussed, there is a race on the PID here, as it may have been reused for
"excel.exe" or some other process.
There are many ways to close the race, for example by redoing the window lookup
and the ::GetWindowThreadProcessId here. 

As-is, the race already exists, but at worst it'll kill a random process on the
user's system :/

[manzagop (departed), 2016/04/01 16:09:00]

Done.

+  // Capture a failed rendez-vous hang report of the other process. Kasko needs
+  // the exception context to live either in the dumper of the dumpee. This
+  // means we cannot rely on kasko reporters from either browser watcher, and
+  // instead spin up a new reporter. Note that we will exit shortly after
+  // capturing the report, meaning the report may not get uploaded by this
+  // reporter.
+  // DO NOT SUBMIT: add a build flag for capturign RDV hangs
+  // #if BUILDFLAG(ENABLE_KASKO_RDV_HANG_REPORTS)
+  // TODO(manzagop): add a metric for the number of captured hang reports, for
+  //   comparison with uploaded count?
+
+  // Check the channel
+  // DO NOT SUBMIT: only on canary.
+  // base::string16 channel_name = GoogleUpdateSettings::GetChromeChannel(!InstallUtil::IsPerUserInstall(cmd_line.GetProgram()));
+  // if (base::StringPiece16(channel_name) == L"" ||
+  //     base::StringPiece16(channel_name) == installer::kChromeChannelCanary)
+
+  base::FilePath data_base_dir;
+  chrome::GetDefaultUserDataDirectory(&data_base_dir);
+  base::string16 endpoint =
+      L"chrome_kasko_hangs_" +
+      base::UintToString16(base::Process::Current().Pid());
+
+  bool launched_kasko =
+      InitializeKaskoReporter(endpoint, data_base_dir.value().c_str());
+  if (launched_kasko) {
+    // DO NOT SUBMIT: add a specific crash keys (RDV hang).
+    DumpHungProcess(thread_id, installer::kChromeChannelCanary, process);
+    ShutdownKaskoReporter();
+  }
+#endif  // BUILDFLAG(ENABLE_KASKO)
+
+  // Scan for every window to find a visible one.
   bool visible_window = false;
   ::EnumThreadWindows(thread_id,
                       &BrowserWindowEnumeration,