QtWebEngineProcess.exe crashed on some pc when the number of QWebEnginePage more than 40.

[Lankin]

To use Qt5.6, I port Webkit(Qt5.4.1) to WebEngine(Qt5.6.0), and then I find a bug that When I open page more than 40(ranging from 30 to 40),QtWebEnginePorcess crashed. 
I tried the "WebEngine Demo Brower Example", When I open new tab more than 40, it crash too.
I tried Qt5.6.1 and Qt5.7.0, the same problem exist too.
some crash info:

(1)open too many(40) QWebEnginePage, it became black and print error:
ARB::createContext: wglCreateContextAttribsARB() failed (GL error code: 0x500) for format: QSurfaceFormat(version 2.0, options QFlags(), depthBufferSize 24, redBufferSize -1, greenBufferSize -1, blueBufferSize -1, alphaBufferSize -1, stencilBufferSize 8, samples 0, swapBehavior 0, swapInterval 1, profile 0), shared context: 0x10003 ()
GDI::createContext: wglCreateContext failed. ()
Unable to create a GL Context.
QOpenGLWidget: Failed to create context
ARB::createContext: wglCreateContextAttribsARB() failed (GL error code: 0x0) for format: QSurfaceFormat(version 2.0, options QFlags(), depthBufferSize 24, redBufferSize -1, greenBufferSize -1, blueBufferSize -1, alphaBufferSize -1, stencilBufferSize 8, samples 0, swapBehavior 0, swapInterval 1, profile 0), shared context: 0x10003 ()
GDI::createContext: wglCreateContext failed. ()
Unable to create a GL Context.
QOpenGLWidget: Failed to create context

(2)QtWebEngineProcess.exe crashed
Qt5WebEngineCored.dll!base::debug::BreakDebugger(void) C++
Qt5WebEngineCored.dll!logging::LogMessage::~LogMessage(void) C++
Qt5WebEngineCored.dll!base::`anonymous namespace'::OnNoMemory(unsigned int) C++
Qt5WebEngineCored.dll!base::TerminateBecauseOutOfMemory(unsigned int) C++

Qt5WebEngineCored.dll!content::ChildDiscardableSharedMemoryManager::AllocateLockedDiscardableSharedMemory(unsigned int,int) C++
Qt5WebEngineCored.dll!content::ChildDiscardableSharedMemoryManager::AllocateLockedDiscardableMemory(unsigned int) C++
Qt5WebEngineCored.dll!content::WebDiscardableMemoryImpl::CreateLockedMemory(unsigned int) C++
Qt5WebEngineCored.dll!content::BlinkPlatformImpl::allocateAndLockDiscardableMemory(unsigned int) C++

(3)crash screenshot and break pointer:

Any one can help?

[Lankin]

By the way, chrome run very well on my pc,I open more than 70 page, and it display normal. Just QtWebEngine has this problem.When I open new webengine page, it use too many memory. It troubled me four days, any help will be grateful!