[Sampling profiler] CHECK on OpenThread result

The failure of OpenThread to return a valid handle is the suspected
cause of the crash in the associated bug. This check is intended to
validate that suspicion.

Bug: 947459
Change-Id: I55e59bf903e5383d9def56c3c57f3b8b4de5182f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1600315
Auto-Submit: Mike Wittman <wittman@chromium.org>
Commit-Queue: Charlie Andrews <charliea@chromium.org>
Reviewed-by: Charlie Andrews <charliea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#657749}

base/profiler/thread_delegate_win.cc

@@ -7,6 +7,7 @@
 #include <windows.h>
 #include <winternl.h>
 
+#include "base/logging.h"
 #include "base/profiler/native_unwinder_win.h"
 #include "build/build_config.h"
 
@@ -27,6 +28,14 @@ struct TEB {
   // Rest of struct is ignored.
 };
 
+win::ScopedHandle GetThreadHandle(PlatformThreadId thread_id) {
+  win::ScopedHandle handle(::OpenThread(
+      THREAD_GET_CONTEXT | THREAD_SUSPEND_RESUME | THREAD_QUERY_INFORMATION,
+      FALSE, thread_id));
+  CHECK(handle.IsValid());
+  return handle;
+}
+
 // Returns the thread environment block pointer for |thread_handle|.
 const TEB* GetThreadEnvironmentBlock(HANDLE thread_handle) {
   // Define the internal types we need to invoke NtQueryInformationThread.
@@ -148,10 +157,7 @@ bool ThreadDelegateWin::ScopedSuspendThread::WasSuccessful() const {
 // ThreadDelegateWin ----------------------------------------------------------
 
 ThreadDelegateWin::ThreadDelegateWin(PlatformThreadId thread_id)
-    : thread_handle_(::OpenThread(
-          THREAD_GET_CONTEXT | THREAD_SUSPEND_RESUME | THREAD_QUERY_INFORMATION,
-          FALSE,
-          thread_id)),
+    : thread_handle_(GetThreadHandle(thread_id)),
       thread_stack_base_address_(reinterpret_cast<uintptr_t>(
           GetThreadEnvironmentBlock(thread_handle_.Get())->Tib.StackBase)) {}