[bgmode] Log the unpin stack trace to Crash Keys

chrome/common/crash_keys.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/crash_keys.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
@@ skipping 15 matching lines @@
 namespace crash_keys {
 
 const char kActiveURL[] = "url-chunk";
 
 const char kFontKeyName[] = "font_key_name";
 
 const char kExtensionID[] = "extension-%" PRIuS;
 const char kNumExtensionsCount[] = "num-extensions";
 
 const char kShutdownType[] = "shutdown-type";
+const char kBrowserUnpinTrace[] = "browser-unpin-trace";

[sky, 2016/12/14 16:34:03]

keep sorted?

 
 #if !defined(OS_ANDROID)
 const char kGPUVendorID[] = "gpu-venid";
 const char kGPUDeviceID[] = "gpu-devid";
 #endif
 const char kGPUDriverVersion[] = "gpu-driver";
 const char kGPUPixelShaderVersion[] = "gpu-psver";
 const char kGPUVertexShaderVersion[] = "gpu-vsver";
 #if defined(OS_MACOSX)
 const char kGPUGLVersion[] = "gpu-glver";
@@ skipping 336 matching lines @@
 }
 
 ScopedPrinterInfo::~ScopedPrinterInfo() {
   for (size_t i = 0; i < kPrinterInfoCount; ++i) {
     std::string key = base::StringPrintf(kPrinterInfo, i + 1);
     base::debug::ClearCrashKey(key);
   }
 }
 
 }  // namespace crash_keys