Fix return type of SetProcessDpiAwareness aka SetProcessDpiAwarenessInternal

This function (documented as SetProcessDpiAwareness but exported as
SetProcessDpiAwarenessInternal) has a return type of HRESULT but we
declared it as returning BOOL. This triggered the following /analyze
warning:

src\chrome\app\chrome_exe_main_win.cc(104) : warning C6216:
   Compiler-inserted cast between semantically different integral
   types:  a Boolean type to HRESULT.

BUG=427616

Review URL: https://codereview.chromium.org/691903002

Cr-Commit-Position: refs/heads/master@{#302212}

chrome/app/chrome_exe_main_win.cc

@@ -95,7 +95,7 @@ typedef enum MONITOR_DPI_TYPE {
 
 // Win8.1 supports monitor-specific DPI scaling.
 bool SetProcessDpiAwarenessWrapper(PROCESS_DPI_AWARENESS value) {
-  typedef BOOL(WINAPI *SetProcessDpiAwarenessPtr)(PROCESS_DPI_AWARENESS);
+  typedef HRESULT(WINAPI *SetProcessDpiAwarenessPtr)(PROCESS_DPI_AWARENESS);
   SetProcessDpiAwarenessPtr set_process_dpi_awareness_func =
       reinterpret_cast<SetProcessDpiAwarenessPtr>(
           GetProcAddress(GetModuleHandleA("user32.dll"),