debugger: Abandon context when Qt changes it without notice

Qt changes the context on many conditions. Abandon GrContext
in these cases.

Also call GrContext::resetContext during Qt GL paint callback,
the GL state may be touched by Qt.

Fixes the bug where changing between gpu and msaa would start
erroring in framebuffer binds, if the .skp had many layers.

Review URL: https://codereview.chromium.org/915573002

diff --git a/debugger/QT/SkGLWidget.cpp b/debugger/QT/SkGLWidget.cpp
index 1fbedf1..6720239 100644 (file)
--- a/debugger/QT/SkGLWidget.cpp
+++ b/debugger/QT/SkGLWidget.cpp
@@ -32,19 +32,16 @@ void SkGLWidget::initializeGL() {
     if (!fCurIntf) {
         return;
     }
-    if (!fCurContext) {
-        fCurContext.reset(GrContext::Create(kOpenGL_GrBackend, (GrBackendContext) fCurIntf.get()));
-    }
-    if (!fCurContext) {
-        return;
-    }
-
     // The call may come multiple times, for example after setSampleCount().  The QGLContext will be
     // different, but we do not have a mechanism to catch the destroying of QGLContext, so that
-    // proper resource cleanup could be made. Instead, we assume that the underlying GL context
-    // never actually changes. If it would, we could not destroy the resources.
+    // proper resource cleanup could be made.
+    if (fCurContext) {
+        fCurContext->abandonContext();
+    }
     fGpuDevice.reset(NULL);
     fCanvas.reset(NULL);
+
+    fCurContext.reset(GrContext::Create(kOpenGL_GrBackend, (GrBackendContext) fCurIntf.get()));
 }
 
 void SkGLWidget::createRenderTarget() {
@@ -76,6 +73,7 @@ void SkGLWidget::resizeGL(int w, int h) {
 
 void SkGLWidget::paintGL() {
     if (!this->isHidden() && fCanvas) {
+        fCurContext->resetContext();
         fDebugger->draw(fCanvas.get());
         // TODO(chudy): Implement an optional flush button in Gui.
         fCanvas->flush();