Allow nested state restorers in DrawingBuffer

third_party/WebKit/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 233 matching lines @@
   ScopedStateRestorer scopedStateRestorer(this);
   bool forceGpuResult = false;
   return prepareTextureMailboxInternal(outMailbox, outReleaseCallback,
                                        forceGpuResult);
 }
 
 bool DrawingBuffer::prepareTextureMailboxInternal(
     cc::TextureMailbox* outMailbox,
     std::unique_ptr<cc::SingleReleaseCallback>* outReleaseCallback,
     bool forceGpuResult) {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK(m_stateRestorer);
+  DCHECK(m_stateRestorer);
   if (m_destructionInProgress) {
     // It can be hit in the following sequence.
     // 1. WebGL draws something.
     // 2. The compositor begins the frame.
     // 3. Javascript makes a context lost using WEBGL_lose_context extension.
     // 4. Here.
     return false;
   }
   ASSERT(!m_isHidden);
   if (!m_contentsChanged)
@@ skipping 49 matching lines @@
                         RefPtr<DrawingBuffer>(this),
                         WTF::passed(std::move(bitmap)), m_size);
   *outReleaseCallback =
       cc::SingleReleaseCallback::Create(convertToBaseCallback(std::move(func)));
   return true;
 }
 
 bool DrawingBuffer::finishPrepareTextureMailboxGpu(
     cc::TextureMailbox* outMailbox,
     std::unique_ptr<cc::SingleReleaseCallback>* outReleaseCallback) {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK(m_stateRestorer);
+  DCHECK(m_stateRestorer);
   if (m_webGLVersion > WebGL1) {
     m_stateRestorer->setPixelUnpackBufferBindingDirty();
     m_gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
   }
 
   // Specify the buffer that we will put in the mailbox.
   RefPtr<ColorBuffer> colorBufferForMailbox;
   if (m_preserveDrawingBuffer == Discard) {
     // If we can discard the backbuffer, send the old backbuffer directly
     // into the mailbox, and allocate (or recycle) a new backbuffer.
@@ skipping 227 matching lines @@
         defaultBufferRequiresAlphaChannelToBePreserved() ? GL_RGBA : GL_RGB;
     parameters.creationInternalColorFormat = format;
     parameters.internalColorFormat = format;
     parameters.colorFormat = format;
   }
   return parameters;
 }
 
 PassRefPtr<DrawingBuffer::ColorBuffer>
 DrawingBuffer::createOrRecycleColorBuffer() {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK(m_stateRestorer);
+  DCHECK(m_stateRestorer);
   if (!m_recycledColorBufferQueue.isEmpty()) {
     RefPtr<ColorBuffer> recycled = m_recycledColorBufferQueue.takeLast();
     if (recycled->receiveSyncToken.HasData())
       m_gl->WaitSyncTokenCHROMIUM(recycled->receiveSyncToken.GetData());
     DCHECK(recycled->size == m_size);
     return recycled;
   }
   return createColorBuffer(m_size);
 }
 
@@ skipping 215 matching lines @@
   m_multisampleFBO = 0;
   m_fbo = 0;
 
   if (m_layer)
     GraphicsLayer::unregisterContentsLayer(m_layer->layer());
 
   m_client = nullptr;
 }
 
 bool DrawingBuffer::resizeDefaultFramebuffer(const IntSize& size) {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK(m_stateRestorer);
+  DCHECK(m_stateRestorer);
   // Recreate m_backColorBuffer.
   m_backColorBuffer = createColorBuffer(size);
 
   attachColorBufferToReadFramebuffer();
 
   if (wantExplicitResolve()) {
     m_stateRestorer->setFramebufferBindingDirty();
     m_stateRestorer->setRenderbufferBindingDirty();
     m_gl->BindFramebuffer(GL_FRAMEBUFFER, m_multisampleFBO);
     m_gl->BindRenderbuffer(GL_RENDERBUFFER, m_multisampleRenderbuffer);
@@ skipping 48 matching lines @@
   return m_gl->CheckFramebufferStatus(GL_FRAMEBUFFER) ==
          GL_FRAMEBUFFER_COMPLETE;
 }
 
 void DrawingBuffer::clearFramebuffers(GLbitfield clearMask) {
   ScopedStateRestorer scopedStateRestorer(this);
   clearFramebuffersInternal(clearMask);
 }
 
 void DrawingBuffer::clearFramebuffersInternal(GLbitfield clearMask) {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK(m_stateRestorer);
+  DCHECK(m_stateRestorer);
   m_stateRestorer->setFramebufferBindingDirty();
   // We will clear the multisample FBO, but we also need to clear the
   // non-multisampled buffer.
   if (m_multisampleFBO) {
     m_gl->BindFramebuffer(GL_FRAMEBUFFER, m_fbo);
     m_gl->Clear(GL_COLOR_BUFFER_BIT);
   }
 
   m_gl->BindFramebuffer(GL_FRAMEBUFFER,
                         m_multisampleFBO ? m_multisampleFBO : m_fbo);
@@ skipping 15 matching lines @@
 
   return adjustedSize;
 }
 
 bool DrawingBuffer::resize(const IntSize& newSize) {
   ScopedStateRestorer scopedStateRestorer(this);
   return resizeFramebufferInternal(newSize);
 }
 
 bool DrawingBuffer::resizeFramebufferInternal(const IntSize& newSize) {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK(m_stateRestorer);
-  CHECK(!newSize.isEmpty());
+  DCHECK(m_stateRestorer);
+  DCHECK(!newSize.isEmpty());
   IntSize adjustedSize = adjustSize(newSize, m_size, m_maxTextureSize);
   if (adjustedSize.isEmpty())
     return false;
 
   if (adjustedSize != m_size) {
     do {
       if (!resizeDefaultFramebuffer(adjustedSize)) {
         adjustedSize.scale(s_resourceAdjustedRatio);
         continue;
       }
@@ skipping 34 matching lines @@
 
 void DrawingBuffer::resolveAndBindForReadAndDraw() {
   {
     ScopedStateRestorer scopedStateRestorer(this);
     resolveMultisampleFramebufferInternal();
   }
   m_gl->BindFramebuffer(GL_FRAMEBUFFER, m_fbo);
 }
 
 void DrawingBuffer::resolveMultisampleFramebufferInternal() {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK(m_stateRestorer);
+  DCHECK(m_stateRestorer);
   m_stateRestorer->setFramebufferBindingDirty();
   if (wantExplicitResolve() && !m_contentsChangeCommitted) {
     m_stateRestorer->setClearStateDirty();
     m_gl->BindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, m_multisampleFBO);
     m_gl->BindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, m_fbo);
     m_gl->Disable(GL_SCISSOR_TEST);
 
     int width = m_size.width();
     int height = m_size.height();
     // Use NEAREST, because there is no scale performed during the blit.
@@ skipping 88 matching lines @@
 
   pixels.transfer(contents);
   return true;
 }
 
 void DrawingBuffer::readBackFramebuffer(unsigned char* pixels,
                                         int width,
                                         int height,
                                         ReadbackOrder readbackOrder,
                                         WebGLImageConversion::AlphaOp op) {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK(m_stateRestorer);
+  DCHECK(m_stateRestorer);
   m_stateRestorer->setPixelPackAlignmentDirty();
   m_gl->PixelStorei(GL_PACK_ALIGNMENT, 1);
   m_gl->ReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
 
   size_t bufferSize = 4 * width * height;
 
   if (readbackOrder == ReadbackSkia) {
 #if (SK_R32_SHIFT == 16) && !SK_B32_SHIFT
     // Swizzle red and blue channels to match SkBitmap's byte ordering.
     // TODO(kbr): expose GL_BGRA as extension.
@@ skipping 24 matching lines @@
     uint8_t* rowA = framebuffer + i * rowBytes;
     uint8_t* rowB = framebuffer + (height - i - 1) * rowBytes;
     memcpy(scanline.data(), rowB, rowBytes);
     memcpy(rowB, rowA, rowBytes);
     memcpy(rowA, scanline.data(), rowBytes);
   }
 }
 
 RefPtr<DrawingBuffer::ColorBuffer> DrawingBuffer::createColorBuffer(
     const IntSize& size) {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK(m_stateRestorer);
+  DCHECK(m_stateRestorer);
   m_stateRestorer->setFramebufferBindingDirty();
   m_stateRestorer->setTextureBindingDirty();
 
   // Select the Parameters for the texture object. Allocate the backing
   // GpuMemoryBuffer and GLImage, if one is going to be used.
   ColorBufferParameters parameters;
   GLuint imageId = 0;
   if (shouldUseChromiumImage()) {
     parameters = gpuMemoryBufferColorBufferParameters();
     imageId = m_gl->CreateGpuMemoryBufferImageCHROMIUM(
@@ skipping 53 matching lines @@
     m_gl->Clear(GL_COLOR_BUFFER_BIT);
     m_gl->FramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                                parameters.target, 0, 0);
     m_gl->DeleteFramebuffers(1, &fbo);
   }
 
   return adoptRef(new ColorBuffer(this, parameters, size, textureId, imageId));
 }
 
 void DrawingBuffer::attachColorBufferToReadFramebuffer() {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK(m_stateRestorer);
+  DCHECK(m_stateRestorer);
   m_stateRestorer->setFramebufferBindingDirty();
   m_stateRestorer->setTextureBindingDirty();
 
   m_gl->BindFramebuffer(GL_FRAMEBUFFER, m_fbo);
 
   GLenum target = m_backColorBuffer->parameters.target;
   GLenum id = m_backColorBuffer->textureId;
 
   m_gl->BindTexture(target, id);
 
@@ skipping 23 matching lines @@
   if (contextProvider()
           ->getCapabilities()
           .disable_webgl_rgb_multisampling_usage)
     return GL_RGBA8_OES;
   return GL_RGB8_OES;
 }
 
 DrawingBuffer::ScopedStateRestorer::ScopedStateRestorer(
     DrawingBuffer* drawingBuffer)
     : m_drawingBuffer(drawingBuffer) {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK(!m_drawingBuffer->m_stateRestorer);
+  // If this is a nested restorer, save the previous restorer.
+  m_previousStateRestorer = drawingBuffer->m_stateRestorer;
   m_drawingBuffer->m_stateRestorer = this;
 }
 
 DrawingBuffer::ScopedStateRestorer::~ScopedStateRestorer() {
-  // TODO(ccameron): Make this a DCHECK after fixing crbug.com/658265
-  CHECK_EQ(m_drawingBuffer->m_stateRestorer, this);
-  m_drawingBuffer->m_stateRestorer = nullptr;
+  DCHECK_EQ(m_drawingBuffer->m_stateRestorer, this);
+  m_drawingBuffer->m_stateRestorer = m_previousStateRestorer;
   Client* client = m_drawingBuffer->m_client;
   if (!client)
     return;
 
   if (m_clearStateDirty) {
     client->DrawingBufferClientRestoreScissorTest();
     client->DrawingBufferClientRestoreMaskAndClearValues();
   }
   if (m_pixelPackAlignmentDirty)
     client->DrawingBufferClientRestorePixelPackAlignment();
   if (m_textureBindingDirty)
     client->DrawingBufferClientRestoreTexture2DBinding();
   if (m_renderbufferBindingDirty)
     client->DrawingBufferClientRestoreRenderbufferBinding();
   if (m_framebufferBindingDirty)
     client->DrawingBufferClientRestoreFramebufferBinding();
   if (m_pixelUnpackBufferBindingDirty)
     client->DrawingBufferClientRestorePixelUnpackBufferBinding();
 }
 
 bool DrawingBuffer::shouldUseChromiumImage() {
   return RuntimeEnabledFeatures::webGLImageChromiumEnabled() &&
          m_chromiumImageUsage == AllowChromiumImage;
 }
 
 }  // namespace blink