Prime the Windows theme DLL earlier.

content/app/content_main_runner.cc

Index: content/app/content_main_runner.cc
diff --git a/content/app/content_main_runner.cc b/content/app/content_main_runner.cc
index 4d76ab1f5170d86e479d12bfb8e9bd007a88ab05..c2a4ab13085ab5667d4ef1bfcca04fbb06ce48c3 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -20,6 +20,7 @@
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/profiler/alternate_timer.h"
+#include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/string_number_conversions.h"
 #include "content/browser/browser_main.h"
@@ -55,6 +56,7 @@
 #include <atlbase.h>
 #include <atlapp.h>
 #include <malloc.h>
+#include <string>
 #elif defined(OS_MACOSX)
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/mach_ipc_mac.h"
@@ -95,6 +97,79 @@ extern int ZygoteMain(const MainFunctionParams&,
 }  // namespace content
 #endif
 
+namespace {
+#if defined(OS_WIN)
+// In order to have Theme support, we need to connect to the theme service.
+// This needs to be done before we lock down the renderer. Officially this
+// can be done with OpenThemeData() but it fails unless you pass a valid
+// window at least the first time. Interestingly, the very act of creating a
+// window also sets the connection to the theme service.
+void EnableThemeSupportForRenderer() {
+  HWINSTA current_station = ::GetProcessWindowStation();
+  static const size_t kStaticBufferLength = 32;
+  char static_buffer[kStaticBufferLength];
+  static_buffer[0] = '\0';

[robertshield, 2012/09/06 18:35:56]

char static_buffer[kStaticBufferLength] = "";

[MAD, 2012/09/06 23:57:53]

Done.

+  const char * current_station_name = static_buffer;

[robertshield, 2012/09/06 18:35:56]

nit: const char* current_station_name = static_buffer;

[MAD, 2012/09/06 23:57:53]

Done.

+  // In case our static buffer isn't big enough, we'll use this dynamic one that
+  // will be holding on the allocated char buffer long enough.
+  std::string dynamic_buffer;

[robertshield, 2012/09/06 18:35:56]

Couldn't we simplify this by always using dynamic_buffer? Initialize
dynamic_buffer to an empty string of length kStaticBufferLength:
std::string dynamic_buffer('\0', kStaticBufferLength);

[MAD, 2012/09/06 23:57:53]

Done.

+  DWORD needed_length = 0;
+  if (!::GetUserObjectInformationA(current_station,
+                                   UOI_NAME,
+                                   static_buffer,
+                                   kStaticBufferLength,
+                                   &needed_length)) {
+    DCHECK(needed_length > kStaticBufferLength) << " Windows error: "
+                                                << ::GetLastError();
+    dynamic_buffer.resize(needed_length);
+    if (!::GetUserObjectInformationA(
+        current_station,
+        UOI_NAME,
+        const_cast<char*>(dynamic_buffer.c_str()),

[rvargas (doing something else), 2012/09/06 23:19:21]

WriteInto ?

+        needed_length,
+        &needed_length)) {
+      NOTREACHED() << "Windows error: " << ::GetLastError();
+    }
+    current_station_name = dynamic_buffer.c_str();
+  }
+
+  if (base::strncasecmp(current_station_name, "WinSta0", 7)) {
+    HWINSTA winsta0 = NULL;
+    winsta0 = ::OpenWindowStationA("WinSta0", FALSE, GENERIC_READ);

[robertshield, 2012/09/06 18:35:56]

shorten this to HWINSTA winsta0 = ::OpenWindowStationA("WinSta0", FALSE,
GENERIC_READ);

[MAD, 2012/09/06 23:57:53]

Done.

+    if (!winsta0 || !::SetProcessWindowStation(winsta0)) {
+      // Could not set the alternate window station. There is a possibility
+      // that the theme wont be correctly initialized.
+      NOTREACHED() << "Unable to switch to WinSta0, we: "<< ::GetLastError();
+    }
+
+    HWND window = ::CreateWindowExW(0, L"Static", L"", WS_POPUP | WS_DISABLED,
+                                    CW_USEDEFAULT, 0, 0, 0,  HWND_MESSAGE, NULL,
+                                    ::GetModuleHandleA(NULL), NULL);
+    if (!window) {
+      DLOG(WARNING) << "failed to enable theme support";
+    } else {
+      ::DestroyWindow(window);
+      window = NULL;
+    }
+
+    // Revert the window station.
+    if (!current_station || !::SetProcessWindowStation(current_station)) {

[robertshield, 2012/09/06 18:35:56]

is it possible to get here if current_station is NULL?

[MAD, 2012/09/06 23:57:53]

Done.

+      // We failed to switch back to the secure window station. This might
+      // confuse the renderer enough that we should kill it now.
+      LOG(FATAL) << "Failed to restore alternate window station";
+    }
+
+    if (!::CloseWindowStation(winsta0)) {
+      // We might be leaking a winsta0 handle.  This is a security risk, but
+      // since we allow fail over to no desktop protection in low memory
+      // condition, this is not a big risk.
+      NOTREACHED();
+    }
+  }
+}
+#endif  // defined(OS_WIN)
+}  // namespace
+
 namespace content {
 
 base::LazyInstance<ContentBrowserClient>
@@ -563,6 +638,10 @@ static void ReleaseFreeMemoryThunk() {
       SendTaskPortToParentProcess();
     }
 #elif defined(OS_WIN)
+    // This must be done early enough since some helper functions like
+    // IsTouchEnanble, needed to load ressources, may call into the theme dll.

[robertshield, 2012/09/06 18:35:56]

*IsTouchEnabled, *resources

[MAD, 2012/09/06 23:57:53]

Done.

+    if (process_type == switches::kRendererProcess)
+      EnableThemeSupportForRenderer();
 #if defined(ENABLE_HIDPI)
     ui::EnableHighDPISupport();
 #endif