Switch chrome_elf exception handling from breakpad to crashpad.

chrome/common/child_process_logging_win.cc

 // Copyright (c) 2012 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/child_process_logging.h"
 
 #include <windows.h>
 
 #include <memory>
 
@@ skipping 11 matching lines @@
 // exported in breakpad_win.cc/crashpad_win.cc:
 //    void __declspec(dllexport) __cdecl SetCrashKeyValueImpl.
 typedef void(__cdecl* SetCrashKeyValue)(const wchar_t*, const wchar_t*);
 
 // exported in breakpad_win.cc/crashpad_win.cc:
 //    void __declspec(dllexport) __cdecl ClearCrashKeyValueImpl.
 typedef void(__cdecl* ClearCrashKeyValue)(const wchar_t*);
 
 void SetCrashKeyValueTrampoline(const base::StringPiece& key,
                                 const base::StringPiece& value) {
-  static SetCrashKeyValue set_crash_key = [](){
-    HMODULE exe_module = GetModuleHandle(chrome::kBrowserProcessExecutableName);
+  static SetCrashKeyValue set_crash_key = []() {
+    HMODULE elf_module = GetModuleHandle(L"chrome_elf.dll");
     return reinterpret_cast<SetCrashKeyValue>(
-        exe_module ? GetProcAddress(exe_module, "SetCrashKeyValueImpl")
+        elf_module ? GetProcAddress(elf_module, "SetCrashKeyValueImpl")
                    : nullptr);
   }();
   if (set_crash_key) {
     (set_crash_key)(base::UTF8ToWide(key).data(),
                     base::UTF8ToWide(value).data());
   }
 }
 
 void ClearCrashKeyValueTrampoline(const base::StringPiece& key) {
-  static ClearCrashKeyValue clear_crash_key = [](){
-    HMODULE exe_module = GetModuleHandle(chrome::kBrowserProcessExecutableName);
+  static ClearCrashKeyValue clear_crash_key = []() {
+    HMODULE elf_module = GetModuleHandle(L"chrome_elf.dll");
     return reinterpret_cast<ClearCrashKeyValue>(
-        exe_module ? GetProcAddress(exe_module, "ClearCrashKeyValueImpl")
+        elf_module ? GetProcAddress(elf_module, "ClearCrashKeyValueImpl")
                    : nullptr);
   }();
   if (clear_crash_key)
     (clear_crash_key)(base::UTF8ToWide(key).data());
 }
 
 }  // namespace
 
 void Init() {
-  crash_keys::RegisterChromeCrashKeys();
-  base::debug::SetCrashKeyReportingFunctions(&SetCrashKeyValueTrampoline,
-                                             &ClearCrashKeyValueTrampoline);
-
   // This would be handled by BreakpadClient::SetCrashClientIdFromGUID(), but
   // because of the aforementioned issue, crash keys aren't ready yet at the
   // time of Breakpad initialization, load the client id backed up in Google
   // Update settings instead.
+  // Please note if we are using CrashPad via chrome_elf then we need to call

[scottmg, 2016/06/27 19:37:46]

nit; CrashPad -> Crashpad

[ananta, 2016/06/27 20:00:26]

Done.

+  // into chrome_elf to pass in the client id.
   std::unique_ptr<metrics::ClientInfo> client_info =
       GoogleUpdateSettings::LoadMetricsClientInfo();
-  if (client_info)
-    crash_keys::SetMetricsClientIdFromGUID(client_info->client_id);
+
+  // Register crash keys using chrome_elf if it is loaded. This is because
+  // chrome_elf and chrome and other executables have their own copies of
+  // base.
+  // TODO(ananta)
+  // Remove this when the change to not require crash key registration lands.
+  HMODULE elf_module = GetModuleHandle(L"chrome_elf.dll");
+  if (elf_module) {
+    using RegisterCrashKeysFunction = void (*)(const char* client_id);
+    RegisterCrashKeysFunction register_keys_fn =
+        reinterpret_cast<RegisterCrashKeysFunction>(
+            ::GetProcAddress(elf_module, "RegisterCrashKeysImpl"));
+    DCHECK(register_keys_fn);
+    register_keys_fn(client_info ? client_info->client_id.c_str() : nullptr);
+  } else {
+    crash_keys::RegisterChromeCrashKeys();

[scottmg, 2016/06/27 20:09:24]

I'm confused now, when is the non-elf path going to be taken (since this is
chrome-only and _win only)?

+    if (client_info)

[scottmg, 2016/06/27 19:37:46]

This should be out of the if/else I think?

[ananta, 2016/06/27 20:00:26]

No. If exception handling is being done by chrome_elf then that function
internally calls crash_keys::SetMetricsClientIdFromGUID

[scottmg, 2016/06/27 20:09:24]

Ah, OK. Let's call RegisterCrashKeysImpl something else then, otherwise we might
forget to keep that part of it once we no longer need to pre-register crash
keys. "RegisterCrashKeysAndSetMetricsId" or something.

[ananta, 2016/06/27 20:36:05]

Done.

+      crash_keys::SetMetricsClientIdFromGUID(client_info->client_id);
+  }
+
+  base::debug::SetCrashKeyReportingFunctions(&SetCrashKeyValueTrampoline,
+                                             &ClearCrashKeyValueTrampoline);
 }
 
 }  // namespace child_process_logging