[bgmode] Log the unpin stack trace to Crash Keys

BUG=625646

Review-Url: https://codereview.chromium.org/2569953003
Cr-Commit-Position: refs/heads/master@{#439176}

blimp/engine/app/blimp_engine_crash_keys.cc

@@ -25,6 +25,7 @@ size_t RegisterEngineCrashKeys() {
       { crash_keys::kVariations, crash_keys::kLargeSize },
 
       // browser/:
+      { "browser-unpin-trace", crash_keys::kMediumSize},
       { "third-party-modules-loaded", crash_keys::kSmallSize },
       { "third-party-modules-not-loaded", crash_keys::kSmallSize },
       { "enrolled-to-domain", crash_keys::kSmallSize },

chrome/app/chrome_crash_reporter_client_win.cc

@@ -40,6 +40,7 @@ constexpr size_t kExtensionIDMaxCount = 10;
 constexpr char kExtensionID[] = "extension-%" PRIuS;
 
 constexpr char kShutdownType[] = "shutdown-type";
+constexpr char kBrowserUnpinTrace[] = "browser-unpin-trace";
 
 constexpr char kGPUVendorID[] = "gpu-venid";
 constexpr char kGPUDeviceID[] = "gpu-devid";
@@ -97,6 +98,7 @@ size_t RegisterCrashKeysHelper() {
       {kVariations, kLargeSize},
       {kNumExtensionsCount, kSmallSize},
       {kShutdownType, kSmallSize},
+      {kBrowserUnpinTrace, kMediumSize},
       {kGPUVendorID, kSmallSize},
       {kGPUDeviceID, kSmallSize},
       {kGPUDriverVersion, kSmallSize},

chrome/browser/browser_process_impl.cc

@@ -15,7 +15,7 @@
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
-#include "base/debug/alias.h"
+#include "base/debug/crash_logging.h"
 #include "base/debug/leak_annotations.h"
 #include "base/files/file_path.h"
 #include "base/location.h"
@@ -77,6 +77,7 @@
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
+#include "chrome/common/crash_keys.h"
 #include "chrome/common/extensions/chrome_extensions_client.h"
 #include "chrome/common/extensions/extension_process_policy.h"
 #include "chrome/common/features.h"
@@ -1314,10 +1315,9 @@ void BrowserProcessImpl::Pin() {
 
   // CHECK(!IsShuttingDown());
   if (IsShuttingDown()) {
-    // Copy the stacktrace which released the final reference onto our stack so
-    // it will be available in the crash report for inspection.
-    base::debug::StackTrace callstack = release_last_reference_callstack_;
-    base::debug::Alias(&callstack);
+    // TODO(crbug.com/113031, crbug.com/625646): Temporary instrumentation.
+    base::debug::SetCrashKeyToStackTrace(crash_keys::kBrowserUnpinTrace,
+                                         release_last_reference_callstack_);
     CHECK(false);
   }
 }

chrome/common/crash_keys.cc

@@ -33,6 +33,7 @@ const char kExtensionID[] = "extension-%" PRIuS;
 const char kNumExtensionsCount[] = "num-extensions";
 
 const char kShutdownType[] = "shutdown-type";
+const char kBrowserUnpinTrace[] = "browser-unpin-trace";
 
 #if !defined(OS_ANDROID)
 const char kGPUVendorID[] = "gpu-venid";
@@ -118,6 +119,7 @@ size_t RegisterChromeCrashKeys() {
     { kVariations, kLargeSize },
     { kNumExtensionsCount, kSmallSize },
     { kShutdownType, kSmallSize },
+    { kBrowserUnpinTrace, kMediumSize },
 #if !defined(OS_ANDROID)
     { kGPUVendorID, kSmallSize },
     { kGPUDeviceID, kSmallSize },

chrome/common/crash_keys.h

@@ -68,6 +68,11 @@ extern const char kNumExtensionsCount[];
 // "exit" for BROWSER_EXIT, or "end" for END_SESSION.
 extern const char kShutdownType[];
 
+// Stack trace associated to the browser being unpinned and starting the
+// shutdown sequence. The value is set when we trigger a browser crash due to an
+// invalid attempt to Pin the browser process after that.
+extern const char kBrowserUnpinTrace[];
+
 // GPU information.
 #if !defined(OS_ANDROID)
 extern const char kGPUVendorID[];