gpu: Remove WebGraphicsContext3D::makeContextCurrent() in Blink

Source/platform/graphics/Canvas2DLayerBridge.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 43 matching lines @@
     if (!gr)
         return nullptr;
     gr->resetContext();
     SkImageInfo info = SkImageInfo::MakeN32Premul(size.width(), size.height());
     return adoptRef(SkSurface::NewRenderTarget(gr, info,  msaaSampleCount));
 }
 
 PassRefPtr<Canvas2DLayerBridge> Canvas2DLayerBridge::create(const IntSize& size, OpacityMode opacityMode, int msaaSampleCount)
 {
     TRACE_EVENT_INSTANT0("test_gpu", "Canvas2DLayerBridgeCreation");
     OwnPtr<WebGraphicsContext3DProvider> contextProvider = adoptPtr(Platform::current()->createSharedOffscreenGraphicsContext3DProvider());

[dshwang, 2014/08/16 15:21:28]

chromium already did initial bind in
createSharedOffscreenGraphicsContext3DProvider(). It's why we don't call
makeContextCurrent() here.

     if (!contextProvider)
         return nullptr;
     RefPtr<SkSurface> surface(createSkSurface(contextProvider->grContext(), size, msaaSampleCount));
     if (!surface)
         return nullptr;
     RefPtr<Canvas2DLayerBridge> layerBridge;
     OwnPtr<SkDeferredCanvas> canvas = adoptPtr(SkDeferredCanvas::Create(surface.get()));
     layerBridge = adoptRef(new Canvas2DLayerBridge(contextProvider.release(), canvas.release(), surface.release(), msaaSampleCount, opacityMode));
     return layerBridge.release();
 }
@@ skipping 140 matching lines @@
 {
     ASSERT(!m_destructionInProgress);
     ASSERT(m_layer);
     if (!checkSurfaceValid()) {
         if (m_canvas) {
             // drop pending commands because there is no surface to draw to
             m_canvas->silentFlush();
         }
         return;
     }
-    context()->makeContextCurrent();
 }
 
 void Canvas2DLayerBridge::storageAllocatedForRecordingChanged(size_t bytesAllocated)
 {
     ASSERT(!m_destructionInProgress);
     intptr_t delta = (intptr_t)bytesAllocated - (intptr_t)m_bytesAllocated;
     m_bytesAllocated = bytesAllocated;
     Canvas2DLayerManager::get().layerTransientResourceAllocationChanged(this, delta);
 }
 
@@ skipping 165 matching lines @@
         return false;
     }
     if (!checkSurfaceValid())
         return false;
 
     WebGraphicsContext3D* webContext = context();
 
     // Release to skia textures that were previouosly released by the
     // compositor. We do this before acquiring the next snapshot in
     // order to cap maximum gpu memory consumption.
-    webContext->makeContextCurrent();
     flush();
 
     RefPtr<SkImage> image = adoptRef(m_canvas->newImageSnapshot());
 
     // Early exit if canvas was not drawn to since last prepareMailbox
     if (image->uniqueID() == m_lastImageId)
         return false;
     m_lastImageId = image->uniqueID();
 
     MailboxInfo* mailboxInfo = createMailboxInfo();
@@ skipping 145 matching lines @@
 Canvas2DLayerBridge::MailboxInfo::MailboxInfo(const MailboxInfo& other) {
     // This copy constructor should only be used for Vector reallocation
     // Assuming 'other' is to be destroyed, we transfer m_image ownership
     // rather than do a refcount dance.
     memcpy(&m_mailbox, &other.m_mailbox, sizeof(m_mailbox));
     m_image = const_cast<MailboxInfo*>(&other)->m_image.release();
     m_status = other.m_status;
 }
 
 } // namespace blink