Fix state restoration logic in canvas 2d wakeup from hibernation

third_party/WebKit/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 152 matching lines @@
 bool Canvas2DLayerBridge::shouldAccelerate(AccelerationHint hint) const
 {
     bool accelerate;
     if (m_softwareRenderingWhileHidden)
         accelerate = false;
     else if (m_accelerationMode == ForceAccelerationForTesting)
         accelerate = true;
     else if (m_accelerationMode == DisableAcceleration)
         accelerate = false;
     else
-        accelerate = hint == PreferAcceleration;
+        accelerate = hint == PreferAcceleration || hint == PreferAccelerationAfterVisibilityChange;
 
     if (accelerate && (!m_contextProvider || m_contextProvider->context3d()->isContextLost()))
         accelerate = false;
     return accelerate;
 }
 
 bool Canvas2DLayerBridge::isAccelerated() const
 {
     if (isHibernating())
         return false;
@@ skipping 60 matching lines @@
     } else {
         m_logger->reportHibernationEvent(HibernationAbortedDueToAllocationFailure);
     }
 }
 
 SkSurface* Canvas2DLayerBridge::getOrCreateSurface(AccelerationHint hint)
 {
     if (m_surface)
         return m_surface.get();
 
-    if (m_layer && !isHibernating())
+    if (m_layer && !isHibernating() && hint == PreferAcceleration) {
         return nullptr; // re-creation will happen through restore()
+    }
 
     bool wantAcceleration = shouldAccelerate(hint);
     bool surfaceIsAccelerated;
 
     if (isHidden() && wantAcceleration) {
         wantAcceleration = false;
         m_softwareRenderingWhileHidden = true;
     }
 
     m_surface = createSkSurface(wantAcceleration ? m_contextProvider->grContext() : nullptr, m_size, m_msaaSampleCount, m_opacityMode, &surfaceIsAccelerated);
@@ skipping 16 matching lines @@
                 m_logger->reportHibernationEvent(HibernationEndedWithFallbackToSW);
         }
 
         SkPaint copyPaint;
         copyPaint.setXfermodeMode(SkXfermode::kSrc_Mode);
         m_surface->getCanvas()->drawImage(m_hibernationImage.get(), 0, 0, &copyPaint);
         m_hibernationImage.clear();
 
         if (m_imageBuffer)
             m_imageBuffer->updateGPUMemoryUsage();
+
+        if (m_imageBuffer && !m_isDeferralEnabled)
+            m_imageBuffer->resetCanvas(m_surface->getCanvas());
     }
     return m_surface.get();
 }
 
 SkCanvas* Canvas2DLayerBridge::canvas()
 {
     if (!m_isDeferralEnabled) {
         SkSurface* s = getOrCreateSurface();
         return s ? s->getCanvas() : nullptr;
     }
@@ skipping 85 matching lines @@
             m_layer->clearTexture();
         m_logger->reportHibernationEvent(HibernationScheduled);
         Platform::current()->currentThread()->scheduler()->postIdleTask(BLINK_FROM_HERE, WTF::bind<double>(&hibernateWrapper, m_weakPtrFactory.createWeakPtr()));
     }
     if (!isHidden() && m_softwareRenderingWhileHidden) {
         flushRecordingOnly();
         SkPaint copyPaint;
         copyPaint.setXfermodeMode(SkXfermode::kSrc_Mode);
         RefPtr<SkSurface> oldSurface = m_surface.release();
         m_softwareRenderingWhileHidden = false;
-        SkSurface* newSurface = getOrCreateSurface();
+        SkSurface* newSurface = getOrCreateSurface(PreferAccelerationAfterVisibilityChange);
         if (newSurface) {
             oldSurface->draw(newSurface->getCanvas(), 0, 0, &copyPaint);
+            if (m_imageBuffer && !m_isDeferralEnabled) {
+                m_imageBuffer->resetCanvas(m_surface->getCanvas());
+            }
         }
     }
     if (!isHidden() && isHibernating()) {
         getOrCreateSurface(); // Rude awakening
     }
 }
 
 bool Canvas2DLayerBridge::writePixels(const SkImageInfo& origInfo, const void* pixels, size_t rowBytes, int x, int y)
 {
     if (!getOrCreateSurface())
@@ skipping 366 matching lines @@
     m_image = other.m_image;
     m_parentLayerBridge = other.m_parentLayerBridge;
 }
 
 void Canvas2DLayerBridge::Logger::reportHibernationEvent(HibernationEvent event)
 {
     blink::Platform::current()->histogramEnumeration("Canvas.HibernationEvents", event, HibernationEventCount);
 }
 
 } // namespace blink