Well, I found the answer days ago.
There are two windows of Google Chrome with the same class name "Chrome_WidgetWin_1" and I was trying to active the first one, when the useful windows is the second one. So, I searched for the second window and later used SetForegroundWindow() with that window.
The result is:
//Getting the HWND of Chrome
HWND chromeWindow = FindWindow("Chrome_WidgetWin_1", NULL);
HWND chrome = GetWindow(chromeWindow, GW_HWNDNEXT);
//Setting the window to the foreground (implies focus and activating)
SetForegroundWindow(chrome);
Thanks anyways.