This adds a recovery mode to the diagnostics

chrome/app/chrome_main_delegate.cc

Index: chrome/app/chrome_main_delegate.cc
diff --git a/chrome/app/chrome_main_delegate.cc b/chrome/app/chrome_main_delegate.cc
index 66202885e5a43ce7089a33c9e46d7be1c76f512c..f9d3fd74cb8bf4d0dd1fc1a8622de891168f988d 100644
--- a/chrome/app/chrome_main_delegate.cc
+++ b/chrome/app/chrome_main_delegate.cc
@@ -73,6 +73,7 @@
 #include "base/sys_info.h"
 #include "chrome/browser/chromeos/boot_times_loader.h"
 #include "chromeos/chromeos_paths.h"
+#include "chromeos/chromeos_switches.h"
 #endif
 
 #if defined(OS_ANDROID)
@@ -419,6 +420,59 @@ bool ChromeMainDelegate::BasicStartupComplete(int* exit_code) {
   }
 #endif
 
+#if defined(OS_CHROMEOS)
+  // If we are recovering from a crash on ChromeOS, then we will do some
+  // recovery using the diagnostics module, and then continue on. We fake up a
+  // command line to tell it that we want it to recover, and to preserve the
+  // original command line.
+  if (command_line.HasSwitch(chromeos::switches::kLoginUser) ||
+      command_line.HasSwitch(switches::kDiagnosticsRecovery)) {
+    CommandLine interim_command_line(command_line.GetProgram());
+    if (command_line.HasSwitch(switches::kUserDataDir)) {
+      interim_command_line.AppendSwitchPath(
+          switches::kUserDataDir,
+          command_line.GetSwitchValuePath(switches::kUserDataDir));
+    }
+    interim_command_line.AppendSwitch(switches::kDiagnostics);
+    interim_command_line.AppendSwitch(switches::kDiagnosticsRecovery);
+
+    diagnostics::DiagnosticsWriter::FormatType format =
+        diagnostics::DiagnosticsWriter::LOG;
+    if (command_line.HasSwitch(switches::kDiagnosticsFormat)) {
+      std::string format_str =
+          command_line.GetSwitchValueASCII(switches::kDiagnosticsFormat);
+      if (format_str == "machine") {
+        format = diagnostics::DiagnosticsWriter::MACHINE;
+      } else if (format_str == "human") {
+        format = diagnostics::DiagnosticsWriter::HUMAN;
+      } else {
+        DCHECK_EQ("log", format_str);
+      }
+    }
+
+    diagnostics::DiagnosticsWriter writer(format);
+    int diagnostics_exit_code =
+        diagnostics::DiagnosticsController::GetInstance()->Run(command_line,
+                                                               &writer);
+    if (diagnostics_exit_code) {
+      // Diagnostics has failed somehow, so we exit.
+      *exit_code = diagnostics_exit_code;
+      return true;
+    }
+
+    // Now we run the actual recovery tasks.
+    int recovery_exit_code =
+        diagnostics::DiagnosticsController::GetInstance()->RunRecovery(
+            command_line, &writer);
+
+    if (recovery_exit_code) {
+      // Recovery has failed somehow, so we exit.
+      *exit_code = recovery_exit_code;
+      return true;
+    }

[cpu_(ooo_6.6-7.5), 2013/07/25 19:40:56]

shouldn't we return here? in what case it is ok to continue?

[Greg Spencer (Chromium), 2013/07/26 18:51:30]

No, in fact, we want to continue here because the recovery is complete, and we
can now continue to start up and recreate things that have been deleted by the
recovery code.  This is soon enough in the startup sequence that nothing from
the profile should have been initialized yet.

+  }
+#endif
+
   content::SetContentClient(&chrome_content_client_);
 
   return false;