Let canvas decide how to handle the lost resource: WebGL part

Source/platform/graphics/gpu/DrawingBufferTest.cpp

 /*
  * Copyright (C) 2013 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 297 matching lines @@
 
     weakPointer->markContentsChanged();
     weakPointer->mailboxReleased(mailbox2);
     EXPECT_EQ(live, true);
 
     weakPointer->markContentsChanged();
     weakPointer->mailboxReleased(mailbox3);
     EXPECT_EQ(live, false);
 }
 
+TEST_F(DrawingBufferTest, verifyDrawingBufferStaysAliveIfResourcesAreLost)
+{
+    bool live = true;
+    m_drawingBuffer->m_live = &live;
+    blink::WebExternalTextureMailbox mailbox1;
+    blink::WebExternalTextureMailbox mailbox2;
+    blink::WebExternalTextureMailbox mailbox3;
+
+    m_drawingBuffer->markContentsChanged();
+    EXPECT_TRUE(m_drawingBuffer->prepareMailbox(&mailbox1, 0));
+    m_drawingBuffer->markContentsChanged();
+    EXPECT_TRUE(m_drawingBuffer->prepareMailbox(&mailbox2, 0));
+    m_drawingBuffer->markContentsChanged();
+    EXPECT_TRUE(m_drawingBuffer->prepareMailbox(&mailbox3, 0));
+
+    m_drawingBuffer->markContentsChanged();
+    m_drawingBuffer->mailboxReleased(mailbox1, true);
+    EXPECT_EQ(live, true);
+
+    m_drawingBuffer->beginDestruction();
+    EXPECT_EQ(live, true);
+
+    m_drawingBuffer->markContentsChanged();
+    m_drawingBuffer->mailboxReleased(mailbox2, false);
+    EXPECT_EQ(live, true);
+
+    DrawingBufferForTests* weakPtr = m_drawingBuffer.get();
+    m_drawingBuffer.clear();
+    EXPECT_EQ(live, true);
+
+    weakPtr->markContentsChanged();
+    weakPtr->mailboxReleased(mailbox3, true);
+    EXPECT_EQ(live, false);
+}
+
 class TextureMailboxWrapper {
 public:
     explicit TextureMailboxWrapper(const blink::WebExternalTextureMailbox& mailbox)
         : m_mailbox(mailbox)
     { }
 
     bool operator==(const TextureMailboxWrapper& other) const
     {
         return !memcmp(m_mailbox.name, other.m_mailbox.name, sizeof(m_mailbox.name));
     }
@@ skipping 290 matching lines @@
         } else {
             EXPECT_EQ(0u, trackingContext->stencilAttachment());
             EXPECT_EQ(0u, trackingContext->depthAttachment());
         }
 
         drawingBuffer->beginDestruction();
     }
 }
 
 } // namespace