Merge 145856 "Check to ensure MultisampleRenderbuffer creation s..."

Source/WebCore/platform/graphics/gpu/DrawingBuffer.cpp

Index: Source/WebCore/platform/graphics/gpu/DrawingBuffer.cpp
===================================================================
--- Source/WebCore/platform/graphics/gpu/DrawingBuffer.cpp	(revision 146669)
+++ Source/WebCore/platform/graphics/gpu/DrawingBuffer.cpp	(working copy)
@@ -189,6 +189,33 @@
     }
 }
 
+// Only way to ensure that we're not getting a bad framebuffer on some AMD/OSX devices.
+// FIXME: This can be removed once renderbufferStorageMultisample starts reporting GL_OUT_OF_MEMORY properly.
+bool DrawingBuffer::checkBufferIntegrity()
+{
+    if (!m_multisampleFBO)
+        return true;
+
+    if (m_scissorEnabled)
+        m_context->disable(GraphicsContext3D::SCISSOR_TEST);
+
+    m_context->colorMask(true, true, true, true);
+
+    m_context->bindFramebuffer(GraphicsContext3D::FRAMEBUFFER, m_multisampleFBO);
+    m_context->clearColor(1.0f, 0.0f, 1.0f, 1.0f);
+    m_context->clear(GraphicsContext3D::COLOR_BUFFER_BIT);
+
+    commit(0, 0, 1, 1);
+
+    unsigned char pixel[4] = {0, 0, 0, 0};
+    m_context->readPixels(0, 0, 1, 1, GraphicsContext3D::RGBA, GraphicsContext3D::UNSIGNED_BYTE, &pixel);
+
+    if (m_scissorEnabled)
+        m_context->enable(GraphicsContext3D::SCISSOR_TEST);
+
+    return (pixel[0] == 0xFF && pixel[1] == 0x00 && pixel[2] == 0xFF && pixel[3] == 0xFF);
+}
+
 bool DrawingBuffer::reset(const IntSize& newSize)
 {
     if (!m_context)
@@ -238,7 +265,6 @@
             internalRenderbufferFormat = Extensions3D::RGB8_OES;
         }
 
-
         do {
             m_size = adjustedSize;
             // resize multisample FBO
@@ -252,6 +278,12 @@
 
                 m_context->bindRenderbuffer(GraphicsContext3D::RENDERBUFFER, m_multisampleColorBuffer);
                 m_context->getExtensions()->renderbufferStorageMultisample(GraphicsContext3D::RENDERBUFFER, sampleCount, internalRenderbufferFormat, m_size.width(), m_size.height());
+
+                if (m_context->getError() == GraphicsContext3D::OUT_OF_MEMORY) {
+                    adjustedSize.scale(s_resourceAdjustedRatio);
+                    continue;
+                }
+
                 m_context->framebufferRenderbuffer(GraphicsContext3D::FRAMEBUFFER, GraphicsContext3D::COLOR_ATTACHMENT0, GraphicsContext3D::RENDERBUFFER, m_multisampleColorBuffer);
                 resizeDepthStencil(sampleCount);
                 if (m_context->checkFramebufferStatus(GraphicsContext3D::FRAMEBUFFER) != GraphicsContext3D::FRAMEBUFFER_COMPLETE) {
@@ -278,10 +310,21 @@
 
             if (!multisample())
                 resizeDepthStencil(0);
-            if (m_context->checkFramebufferStatus(GraphicsContext3D::FRAMEBUFFER) == GraphicsContext3D::FRAMEBUFFER_COMPLETE)
-                break;
-            adjustedSize.scale(s_resourceAdjustedRatio);
+            if (m_context->checkFramebufferStatus(GraphicsContext3D::FRAMEBUFFER) != GraphicsContext3D::FRAMEBUFFER_COMPLETE) {
+                adjustedSize.scale(s_resourceAdjustedRatio);
+                continue;
+            }
 
+#if OS(DARWIN)
+            // FIXME: This can be removed once renderbufferStorageMultisample starts reporting GL_OUT_OF_MEMORY properly on OSX.
+            if (!checkBufferIntegrity()) {
+                adjustedSize.scale(s_resourceAdjustedRatio);
+                continue;
+            }
+#endif
+
+            break;
+
         } while (!adjustedSize.isEmpty());
 
         pixelDelta = m_size.width() * m_size.height();