Let canvas decide how to handle the case of resource lost reported by client: 2D part

Source/platform/graphics/gpu/DrawingBuffer.cpp

 /*
  * Copyright (c) 2010, 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 258 matching lines @@
     markLayerComposited();
 
     // set m_parentDrawingBuffer to make sure 'this' stays alive as long as it has live mailboxes
     ASSERT(!frontColorBufferMailbox->m_parentDrawingBuffer);
     frontColorBufferMailbox->m_parentDrawingBuffer = this;
     *outMailbox = frontColorBufferMailbox->mailbox;
     m_frontColorBuffer = frontColorBufferMailbox->textureInfo;
     return true;
 }
 
-void DrawingBuffer::mailboxReleased(const blink::WebExternalTextureMailbox& mailbox)
+void DrawingBuffer::mailboxReleased(const blink::WebExternalTextureMailbox& mailbox, bool lostResource)
 {
-    if (m_destructionInProgress) {
+    if (m_destructionInProgress || m_context->isContextLost() || lostResource) {

[Ken Russell (switch to Gerrit), 2014/07/15 22:22:33]

Could you please add a new test to DrawingBufferTest.cpp which verifies the
behavior when mailboxRelease is called with lostResource=true?

         mailboxReleasedWhileDestructionInProgress(mailbox);
         return;
     }
 
     for (size_t i = 0; i < m_textureMailboxes.size(); i++) {
         RefPtr<MailboxInfo> mailboxInfo = m_textureMailboxes[i];
         if (nameEquals(mailboxInfo->mailbox, mailbox)) {
             mailboxInfo->mailbox.syncPoint = mailbox.syncPoint;
             ASSERT(mailboxInfo->m_parentDrawingBuffer.get() == this);
             mailboxInfo->m_parentDrawingBuffer.clear();
@@ skipping 55 matching lines @@
 void DrawingBuffer::deleteMailbox(const blink::WebExternalTextureMailbox& mailbox)
 {
     for (size_t i = 0; i < m_textureMailboxes.size(); i++) {
         if (nameEquals(m_textureMailboxes[i]->mailbox, mailbox)) {
             if (mailbox.syncPoint)
                 m_context->waitSyncPoint(mailbox.syncPoint);
 
             deleteChromiumImageForTexture(&m_textureMailboxes[i]->textureInfo);
 
             m_context->deleteTexture(m_textureMailboxes[i]->textureInfo.textureId);
+            m_textureMailboxes[i]->m_parentDrawingBuffer.clear();

[Ken Russell (switch to Gerrit), 2014/07/15 22:22:33]

Why is this necessary? The call to m_textureMailboxes.remove(i), below, should
cause the MailboxInfo to be deleted and its m_parentDrawingBuffer field cleared.

             m_textureMailboxes.remove(i);
             return;
         }
     }
     ASSERT_NOT_REACHED();
 }
 
 bool DrawingBuffer::initialize(const IntSize& size)
 {
     if (!m_context->makeContextCurrent()) {
@@ skipping 696 matching lines @@
 void DrawingBuffer::deleteChromiumImageForTexture(TextureInfo* info)
 {
     if (info->imageId) {
         m_context->releaseTexImage2DCHROMIUM(GL_TEXTURE_2D, info->imageId);
         m_context->destroyImageCHROMIUM(info->imageId);
         info->imageId = 0;
     }
 }
 
 } // namespace WebCore