Adds the concept of a 'safe mode' hotkey start

chrome/browser/chrome_browser_main_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/browser/chrome_browser_main_win.h"
 
 #include <windows.h>
 #include <shellapi.h>
 
 #include <algorithm>
@@ skipping 33 matching lines @@
 #include "grit/app_locale_settings.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "installer_util_strings/installer_util_strings.h"
 #include "ui/base/cursor/cursor_loader_win.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/l10n_util_win.h"
 #include "ui/base/ui_base_switches.h"
 #include "ui/base/win/message_box_win.h"
 #include "ui/gfx/platform_font_win.h"
+#include "ui/gfx/switches.h"
 
 namespace {
 
 typedef HRESULT (STDAPICALLTYPE* RegisterApplicationRestartProc)(
     const wchar_t* command_line,
     DWORD flags);
 
 void InitializeWindowProcExceptions() {
   // Get the breakpad pointer from chrome.exe
   base::win::WinProcExceptionFilter exception_filter =
@@ skipping 15 matching lines @@
   base::StringToInt(l10n_util::GetStringUTF16(IDS_MINIMUM_UI_FONT_SIZE),
                     &min_font_size);
   return min_font_size;
 }
 
 class TranslationDelegate : public installer::TranslationDelegate {
  public:
   virtual string16 GetLocalizedString(int installer_string_id) OVERRIDE;
 };
 
+// There is a special shortcut that you can start Chrome with that
+// puts it in a safe mode. Used for troubleshooting end-user issues.
+bool IsSafeModeStart() {
+  STARTUPINFOW si = {0};
+  ::GetStartupInfo(&si);
+  if ((si.dwFlags & STARTF_USEHOTKEY) == 0)
+    return false;
+  BrowserDistribution* dist = BrowserDistribution::GetDistribution();
+  return (reinterpret_cast<ULONG_PTR>(si.hStdInput) ==
+          static_cast<ULONG_PTR>(dist->GetSafeModeHotkey()));
+}
+
 }  // namespace
 
 void ShowCloseBrowserFirstMessageBox() {
   int message_id = IDS_UNINSTALL_CLOSE_APP;
   if (base::win::GetVersion() >= base::win::VERSION_WIN8 &&
       (ShellIntegration::GetDefaultBrowser() == ShellIntegration::IS_DEFAULT)) {
     message_id = IDS_UNINSTALL_CLOSE_APP_IMMERSIVE;
   }
   chrome::ShowMessageBox(NULL,
                          l10n_util::GetStringUTF16(IDS_PRODUCT_NAME),
@@ skipping 102 matching lines @@
   ChromeBrowserMainParts::PreMainMessageLoopStart();
   if (!parameters().ui_task) {
     // Make sure that we know how to handle exceptions from the message loop.
     InitializeWindowProcExceptions();
   }
 }
 
 int ChromeBrowserMainPartsWin::PreCreateThreads() {
   int rv = ChromeBrowserMainParts::PreCreateThreads();
 
+  if (IsSafeModeStart()) {
+    CommandLine::ForCurrentProcess()->AppendSwitch(switches::kDisableGpu);
+    CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+        switches::kHighDPISupport, "0");
+  }
+
   // TODO(viettrungluu): why don't we run this earlier?
   if (!parsed_command_line().HasSwitch(switches::kNoErrorDialogs) &&
       base::win::GetVersion() < base::win::VERSION_XP) {
     chrome::ShowMessageBox(NULL,
         l10n_util::GetStringUTF16(IDS_PRODUCT_NAME),
         l10n_util::GetStringUTF16(IDS_UNSUPPORTED_OS_PRE_WIN_XP),
         chrome::MESSAGE_BOX_TYPE_WARNING);
   }
 
   return rv;
@@ skipping 186 matching lines @@
   if (resource_id)
     return l10n_util::GetStringUTF16(resource_id);
   return string16();
 }
 
 // static
 void ChromeBrowserMainPartsWin::SetupInstallerUtilStrings() {
   CR_DEFINE_STATIC_LOCAL(TranslationDelegate, delegate, ());
   installer::SetTranslationDelegate(&delegate);
 }