Revert IOSurface CoreAnimation simplifications on ccameron@'s advice.

content/browser/compositor/io_surface_layer_mac.mm

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/compositor/io_surface_layer_mac.h"
 
-#include <sstream>
-
 #include <CoreFoundation/CoreFoundation.h>
 #include <OpenGL/CGLIOSurface.h>
 #include <OpenGL/CGLRenderers.h>
 #include <OpenGL/gl.h>
 #include <OpenGL/OpenGL.h>
 
 #include "base/mac/mac_util.h"
 #include "base/mac/sdk_forward_declarations.h"
-#include "content/browser/gpu/gpu_data_manager_impl.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
+#include "content/browser/renderer_host/compositing_iosurface_context_mac.h"
+#include "content/browser/renderer_host/compositing_iosurface_mac.h"
 #include "ui/base/cocoa/animation_utils.h"
 #include "ui/gfx/size_conversions.h"
-#include "ui/gl/scoped_cgl.h"
 #include "ui/gl/gpu_switching_manager.h"
 
-// Convenience macro for checking errors in the below code.
-#define CHECK_GL_ERROR() do {                                           \
-    GLenum gl_error = glGetError();                                     \
-    LOG_IF(ERROR, gl_error != GL_NO_ERROR) << "GL Error: " << gl_error; \
-  } while (0)
-
-namespace {
-
-// Helper function for logging error codes.
-template<typename T>
-std::string to_string(T value) {
-  std::ostringstream stream;
-  stream << value;
-  return stream.str();
-}
-
-// Helper function posted to destroy textures on a clean stack.
-void DestroyTexture(
-    base::ScopedTypeRef<CGLContextObj> context,
-    base::ScopedCFTypeRef<IOSurfaceRef> io_surface,
-    GLuint texture) {
-  // Destroy the texture before tearing down the context, and while the
-  // IOSurface is still being kept around.
-  CGLSetCurrentContext(context);
-  glDeleteTextures(1, &texture);
-  CGLSetCurrentContext(NULL);
-
-  // Release (and likely destroy) the context.
-  context.reset();
-
-  // Finally release the IOSurface.
-  io_surface.reset();
-}
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// IOSurfaceLayer(Private)
-
-@interface IOSurfaceLayer(Private)
-// Reset the texture and post a task to clean it up.
-- (void)resetTextureAndPostDestroy;
-
-// Force a draw immediately, but only if one was requested.
-- (void)displayIfNeededAndAck;
-
-// Called  when it has been a fixed interval of time and a frame has yet to be
-// drawn.
-- (void)timerFired;
-@end
-
 ////////////////////////////////////////////////////////////////////////////////
 // IOSurfaceLayerHelper
 
 namespace content {
 
-// IOSurfaceLayerHelper provides C++ functionality needed for the
-// IOSurfaceLayer class (interfacing with base::DelayTimer).
-class IOSurfaceLayerHelper {
- public:
-  IOSurfaceLayerHelper(IOSurfaceLayer* layer);
-  ~IOSurfaceLayerHelper();
-  void ResetTimer();
-
- private:
-  void TimerFired();
-
-  // The layer that owns this helper.
-  IOSurfaceLayer* const layer_;
-
-  // The browser places back-pressure on the GPU by not acknowledging swap
-  // calls until they appear on the screen. This can lead to hangs if the
-  // view is moved offscreen (among other things). Prevent hangs by always
-  // acknowledging the frame after timeout of 1/6th of a second  has passed.
-  base::DelayTimer<IOSurfaceLayerHelper> timer_;
-};
-
-
 IOSurfaceLayerHelper::IOSurfaceLayerHelper(
+    IOSurfaceLayerClient* client,
     IOSurfaceLayer* layer)
-        : layer_(layer),
+        : client_(client),
+          layer_(layer),
+          needs_display_(false),
+          has_pending_frame_(false),
+          did_not_draw_counter_(0),
+          is_pumping_frames_(false),
           timer_(
               FROM_HERE,
               base::TimeDelta::FromSeconds(1) / 6,
               this,
               &IOSurfaceLayerHelper::TimerFired) {}
 
 IOSurfaceLayerHelper::~IOSurfaceLayerHelper() {
+  // Any acks that were waiting on this layer to draw will not occur, so ack
+  // them now to prevent blocking the renderer.
+  AckPendingFrame(true);
 }
 
-void IOSurfaceLayerHelper::ResetTimer() {
-  timer_.Reset();
-}
-
-void IOSurfaceLayerHelper::TimerFired() {
-  [layer_ timerFired];
-}
-
-}  // namespace content
-
-////////////////////////////////////////////////////////////////////////////////
-// IOSurfaceLayer
-
-@implementation IOSurfaceLayer
-
-- (id)initWithClient:(content::IOSurfaceLayerClient*)client
-     withScaleFactor:(float)scale_factor {
-  if (self = [super init]) {
-    client_ = client;
-    helper_.reset(new content::IOSurfaceLayerHelper(self));
-    needs_display_ = false;
-    has_pending_frame_ = false;
-    did_not_draw_counter_ = 0;
-    is_pumping_frames_ = false;
-    io_surface_texture_ = 0;
-    cgl_renderer_id_ = 0;
-
-    [self setBackgroundColor:CGColorGetConstantColor(kCGColorWhite)];
-    [self setAnchorPoint:CGPointMake(0, 0)];
-    // Setting contents gravity is necessary to prevent the layer from being
-    // scaled during dyanmic resizes (especially with devtools open).
-    [self setContentsGravity:kCAGravityTopLeft];
-    if ([self respondsToSelector:(@selector(setContentsScale:))])
-      [self setContentsScale:scale_factor];
-  }
-  return self;
-}
-
-- (void)dealloc {
-  DCHECK(!helper_ && !client_);
-  [super dealloc];
-}
-
-- (float)scaleFactor {
-  if ([self respondsToSelector:(@selector(contentsScale))])
-    return [self contentsScale];
-  return 1;
-}
-
-- (int)rendererID {
-  return cgl_renderer_id_;
-}
-
-- (void)timerFired {
-  [self displayIfNeededAndAck];
-}
-
-- (void)resetClient {
-  // Any acks that were waiting on this layer to draw will not occur, so ack
-  // them now to prevent blocking the renderer.
-  [self ackPendingFrame];
-  helper_.reset();
-  client_ = NULL;
-}
-
-- (void)gotFrameWithIOSurface:(IOSurfaceID)io_surface_id
-                withPixelSize:(gfx::Size)pixel_size
-              withScaleFactor:(float)scale_factor {
+void IOSurfaceLayerHelper::GotNewFrame() {
   // A trace value of 2 indicates that there is a pending swap ack. See
   // canDrawInCGLContext for other value meanings.
-  TRACE_COUNTER_ID1("browser", "PendingSwapAck", self, 2);
+  TRACE_COUNTER_ID1("browser", "PendingSwapAck", this, 2);
+
   has_pending_frame_ = true;
   needs_display_ = true;
-  helper_->ResetTimer();
-
-  frame_pixel_size_ = pixel_size;
-
-  // If this is a new IOSurface, open the IOSurface and mark that the
-  // GL texture needs to bind to the new surface.
-  if (!io_surface_ || io_surface_id != IOSurfaceGetID(io_surface_)) {
-    io_surface_.reset(IOSurfaceLookup(io_surface_id));
-    if (!io_surface_) {
-      [self resetTextureAndPostDestroy];
-      content::GpuDataManagerImpl::GetInstance()->AddLogMessage(
-          logging::LOG_ERROR,
-          "IOSurfaceLayer",
-          "Failed to open IOSurface in gotFrameWithIOSurface");
-      if (client_)
-        client_->IOSurfaceLayerHitError();
-    }
-  }
+  timer_.Reset();
 
   // If reqested, draw immediately and don't bother trying to use the
   // isAsynchronous property to ensure smooth animation. If this is while
   // frames are being pumped then ack and display immediately to get a
   // correct-sized frame displayed as soon as possible.
-  if (is_pumping_frames_ ||
-      (client_ && client_->IOSurfaceLayerShouldAckImmediately())) {
-    [self setNeedsDisplayAndDisplayAndAck];
+  if (is_pumping_frames_ || client_->IOSurfaceLayerShouldAckImmediately()) {
+    SetNeedsDisplayAndDisplayAndAck();
   } else {
-    if (![self isAsynchronous])
-      [self setAsynchronous:YES];
+    if (![layer_ isAsynchronous])
+      [layer_ setAsynchronous:YES];
   }
 }
 
-- (BOOL)canDrawInCGLContext:(CGLContextObj)glContext
-                pixelFormat:(CGLPixelFormatObj)pixelFormat
-               forLayerTime:(CFTimeInterval)timeInterval
-                displayTime:(const CVTimeStamp*)timeStamp {
+void IOSurfaceLayerHelper::SetNeedsDisplay() {
+  needs_display_ = true;
+}
+
+bool IOSurfaceLayerHelper::CanDraw() {
   // If we return NO 30 times in a row, switch to being synchronous to avoid
   // burning CPU cycles on this callback.
   if (needs_display_) {
     did_not_draw_counter_ = 0;
   } else {
     did_not_draw_counter_ += 1;
     if (did_not_draw_counter_ == 30)
-      [self setAsynchronous:NO];
+      [layer_ setAsynchronous:NO];
   }
 
   // Add an instantaneous blip to the PendingSwapAck state to indicate
   // that CoreAnimation asked if a frame is ready. A blip up to to 3 (usually
   // from 2, indicating that a swap ack is pending) indicates that we
   // requested a draw. A blip up to 1 (usually from 0, indicating there is no
   // pending swap ack) indicates that we did not request a draw. This would
   // be more natural to do with a tracing pseudo-thread
   // http://crbug.com/366300
-  TRACE_COUNTER_ID1("browser", "PendingSwapAck", self, needs_display_ ? 3 : 1);
-  TRACE_COUNTER_ID1("browser", "PendingSwapAck", self,
+  TRACE_COUNTER_ID1("browser", "PendingSwapAck", this, needs_display_ ? 3 : 1);
+  TRACE_COUNTER_ID1("browser", "PendingSwapAck", this,
                     has_pending_frame_ ? 2 : 0);
 
   return needs_display_;
 }
 
-- (void)ackPendingFrame {
+void IOSurfaceLayerHelper::DidDraw(bool success) {
+  needs_display_ = false;
+  AckPendingFrame(success);
+}
+
+void IOSurfaceLayerHelper::AckPendingFrame(bool success) {
   if (!has_pending_frame_)
     return;
   has_pending_frame_ = false;
-  if (client_)
+  if (success)
     client_->IOSurfaceLayerDidDrawFrame();
+  else
+    client_->IOSurfaceLayerHitError();
   // A trace value of 0 indicates that there is no longer a pending swap ack.
-  TRACE_COUNTER_ID1("browser", "PendingSwapAck", self, 0);
-}
-
-- (void)setNeedsDisplayAndDisplayAndAck {
+  TRACE_COUNTER_ID1("browser", "PendingSwapAck", this, 0);
+}
+
+void IOSurfaceLayerHelper::SetNeedsDisplayAndDisplayAndAck() {
   // Drawing using setNeedsDisplay and displayIfNeeded will result in
   // subsequent canDrawInCGLContext callbacks getting dropped, and jerky
   // animation. Disable asynchronous drawing before issuing these calls as a
   // workaround.
   // http://crbug.com/395827
-  if ([self isAsynchronous])
-    [self setAsynchronous:NO];
-
-  [self setNeedsDisplay];
-  [self displayIfNeededAndAck];
-}
-
-- (void)displayIfNeededAndAck {
+  if ([layer_ isAsynchronous])
+    [layer_ setAsynchronous:NO];
+
+  [layer_ setNeedsDisplay];
+  DisplayIfNeededAndAck();
+}
+
+void IOSurfaceLayerHelper::DisplayIfNeededAndAck() {
   if (!needs_display_)
     return;
 
   // As in SetNeedsDisplayAndDisplayAndAck, disable asynchronous drawing before
   // issuing displayIfNeeded.
   // http://crbug.com/395827
-  if ([self isAsynchronous])
-    [self setAsynchronous:NO];
+  if ([layer_ isAsynchronous])
+    [layer_ setAsynchronous:NO];
 
   // Do not bother drawing while pumping new frames -- wait until the waiting
   // block ends to draw any of the new frames.
   if (!is_pumping_frames_)
-    [self displayIfNeeded];
+    [layer_ displayIfNeeded];
 
   // Calls to setNeedsDisplay can sometimes be ignored, especially if issued
   // rapidly (e.g, with vsync off). This is unacceptable because the failure
   // to ack a single frame will hang the renderer. Ensure that the renderer
   // not be blocked by lying and claiming that we drew the frame.
-  [self ackPendingFrame];
+  AckPendingFrame(true);
+}
+
+void IOSurfaceLayerHelper::TimerFired() {
+  DisplayIfNeededAndAck();
+}
+
+void IOSurfaceLayerHelper::BeginPumpingFrames() {
+  is_pumping_frames_ = true;
+}
+
+void IOSurfaceLayerHelper::EndPumpingFrames() {
+  is_pumping_frames_ = false;
+  DisplayIfNeededAndAck();
+}
+
+}  // namespace content
+
+////////////////////////////////////////////////////////////////////////////////
+// IOSurfaceLayer
+
+@implementation IOSurfaceLayer
+
+- (content::CompositingIOSurfaceMac*)iosurface {
+  return iosurface_.get();
+}
+
+- (content::CompositingIOSurfaceContext*)context {
+  return context_.get();
+}
+
+- (id)initWithClient:(content::IOSurfaceLayerClient*)client
+     withScaleFactor:(float)scale_factor {
+  if (self = [super init]) {
+    helper_.reset(new content::IOSurfaceLayerHelper(client, self));
+
+    iosurface_ = content::CompositingIOSurfaceMac::Create();
+    context_ = content::CompositingIOSurfaceContext::Get(
+        content::CompositingIOSurfaceContext::kCALayerContextWindowNumber);
+    if (!iosurface_.get() || !context_.get()) {
+      LOG(ERROR) << "Failed create CompositingIOSurface or context";
+      [self resetClient];
+      [self release];
+      return nil;
+    }
+
+    [self setBackgroundColor:CGColorGetConstantColor(kCGColorWhite)];
+    [self setAnchorPoint:CGPointMake(0, 0)];
+    // Setting contents gravity is necessary to prevent the layer from being
+    // scaled during dyanmic resizes (especially with devtools open).
+    [self setContentsGravity:kCAGravityTopLeft];
+    if ([self respondsToSelector:(@selector(setContentsScale:))]) {
+      [self setContentsScale:scale_factor];
+    }
+  }
+  return self;
+}
+
+- (void)dealloc {
+  DCHECK(!helper_);
+  [super dealloc];
+}
+
+- (bool)gotFrameWithIOSurface:(IOSurfaceID)io_surface_id
+                withPixelSize:(gfx::Size)pixel_size
+              withScaleFactor:(float)scale_factor {
+  bool result = true;
+  gfx::ScopedCGLSetCurrentContext scoped_set_current_context(
+      context_->cgl_context());
+  result = iosurface_->SetIOSurfaceWithContextCurrent(
+      context_, io_surface_id, pixel_size, scale_factor);
+  return result;
+}
+
+- (void)poisonContextAndSharegroup {
+  context_->PoisonContextAndSharegroup();
+}
+
+- (bool)hasBeenPoisoned {
+  return context_->HasBeenPoisoned();
+}
+
+- (float)scaleFactor {
+  return iosurface_->scale_factor();
+}
+
+- (int)rendererID {
+  return iosurface_->GetRendererID();
+}
+
+- (void)resetClient {
+  helper_.reset();
+}
+
+- (void)gotNewFrame {
+  helper_->GotNewFrame();
+}
+
+- (void)setNeedsDisplayAndDisplayAndAck {
+  helper_->SetNeedsDisplayAndDisplayAndAck();
+}
+
+- (void)displayIfNeededAndAck {
+  helper_->DisplayIfNeededAndAck();
 }
 
 - (void)beginPumpingFrames {
-  is_pumping_frames_ = true;
+  helper_->BeginPumpingFrames();
 }
 
 - (void)endPumpingFrames {
-  is_pumping_frames_ = false;
-  [self displayIfNeededAndAck];
+  helper_->EndPumpingFrames();
 }
 
 // The remaining methods implement the CAOpenGLLayer interface.
 
 - (CGLPixelFormatObj)copyCGLPixelFormatForDisplayMask:(uint32_t)mask {
-  // Create the pixel format object for the context.
-  std::vector<CGLPixelFormatAttribute> attribs;
-  attribs.push_back(kCGLPFADepthSize);
-  attribs.push_back(static_cast<CGLPixelFormatAttribute>(0));
-  if (ui::GpuSwitchingManager::GetInstance()->SupportsDualGpus()) {
-    attribs.push_back(kCGLPFAAllowOfflineRenderers);
-    attribs.push_back(static_cast<CGLPixelFormatAttribute>(1));
-  }
-  attribs.push_back(static_cast<CGLPixelFormatAttribute>(0));
-  GLint number_virtual_screens = 0;
-  base::ScopedTypeRef<CGLPixelFormatObj> pixel_format;
-  CGLError cgl_error = CGLChoosePixelFormat(
-      &attribs.front(), pixel_format.InitializeInto(), &number_virtual_screens);
-  if (cgl_error != kCGLNoError) {
-    content::GpuDataManagerImpl::GetInstance()->AddLogMessage(
-        logging::LOG_ERROR,
-        "IOSurfaceLayer",
-        std::string("Failed to create pixel format object with CGL error ") +
-            to_string(static_cast<int>(cgl_error)));
-    return NULL;
-  }
-  return CGLRetainPixelFormat(pixel_format);
-}
-
-- (void)releaseCGLContext:(CGLContextObj)glContext {
-  // The GL context is being destroyed, so mark the resources as needing to be
-  // recreated.
-  [self resetTextureAndPostDestroy];
-  [super releaseCGLContext:glContext];
+  if (!context_.get())
+    return [super copyCGLPixelFormatForDisplayMask:mask];
+  return CGLRetainPixelFormat(CGLGetPixelFormat(context_->cgl_context()));
+}
+
+- (CGLContextObj)copyCGLContextForPixelFormat:(CGLPixelFormatObj)pixelFormat {
+  if (!context_.get())
+    return [super copyCGLContextForPixelFormat:pixelFormat];
+  return CGLRetainContext(context_->cgl_context());
 }
 
 - (void)setNeedsDisplay {
-  needs_display_ = true;
+  if (helper_)
+    helper_->SetNeedsDisplay();
   [super setNeedsDisplay];
 }
 
+- (BOOL)canDrawInCGLContext:(CGLContextObj)glContext
+                pixelFormat:(CGLPixelFormatObj)pixelFormat
+               forLayerTime:(CFTimeInterval)timeInterval
+                displayTime:(const CVTimeStamp*)timeStamp {
+  if (helper_)
+    return helper_->CanDraw();
+  return NO;
+}
+
 - (void)drawInCGLContext:(CGLContextObj)glContext
              pixelFormat:(CGLPixelFormatObj)pixelFormat
             forLayerTime:(CFTimeInterval)timeInterval
              displayTime:(const CVTimeStamp*)timeStamp {
   TRACE_EVENT0("browser", "IOSurfaceLayer::drawInCGLContext");
 
-  // Create the texture if it has not been created in this context yet.
-  if (!io_surface_texture_) {
-    DCHECK(!io_surface_texture_io_surface_);
-    DCHECK(!io_surface_texture_context_);
-    glGenTextures(1, &io_surface_texture_);
-    glBindTexture(GL_TEXTURE_RECTANGLE_ARB, io_surface_texture_);
-    glTexParameteri(
-        GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glTexParameteri(
-        GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0);
-    io_surface_texture_context_.reset(glContext, base::scoped_policy::RETAIN);
-  }
-  DCHECK(io_surface_texture_context_ == glContext);
-
-  // Associate the IOSurface with this texture, if the underlying IOSurface has
-  // been changed.
-  if (io_surface_ != io_surface_texture_io_surface_) {
-    glBindTexture(GL_TEXTURE_RECTANGLE_ARB, io_surface_texture_);
-    CGLError cgl_error = CGLTexImageIOSurface2D(
-        glContext,
-        GL_TEXTURE_RECTANGLE_ARB,
-        GL_RGBA,
-        IOSurfaceGetWidth(io_surface_),
-        IOSurfaceGetHeight(io_surface_),
-        GL_BGRA,
-        GL_UNSIGNED_INT_8_8_8_8_REV,
-        io_surface_.get(),
-        0 /* plane */);
-    glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0);
-    if (cgl_error == kCGLNoError) {
-      io_surface_texture_io_surface_ = io_surface_;
-    } else {
-      [self resetTextureAndPostDestroy];
-      content::GpuDataManagerImpl::GetInstance()->AddLogMessage(
-          logging::LOG_ERROR,
-          "IOSurfaceLayer",
-          std::string("CGLTexImageIOSurface2D failed with CGL error ") +
-              to_string(cgl_error));
-      if (client_)
-        client_->IOSurfaceLayerHitError();
-    }
-  } else if (!io_surface_) {
-    [self resetTextureAndPostDestroy];
-  }
-
-  // Fill the viewport with the texture. The viewport must be smaller or equal
-  // than the texture, because it is resized as frames arrive.
-  if (io_surface_texture_) {
-    GLint viewport[4];
-    glGetIntegerv(GL_VIEWPORT, viewport);
-    gfx::Size viewport_pixel_size(viewport[2], viewport[3]);
-    DCHECK_LE(
-        viewport_pixel_size.width(),
-        frame_pixel_size_.width());
-    DCHECK_LE(
-        viewport_pixel_size.height(),
-        frame_pixel_size_.height());
-
-    glMatrixMode(GL_PROJECTION);
-    glLoadIdentity();
-    glOrtho(0, viewport_pixel_size.width(),
-            0, viewport_pixel_size.height(), -1, 1);
-    glMatrixMode(GL_MODELVIEW);
-    glLoadIdentity();
-
-    glColor4f(1, 1, 1, 1);
-    glEnable(GL_TEXTURE_RECTANGLE_ARB);
-    glBindTexture(GL_TEXTURE_RECTANGLE_ARB, io_surface_texture_);
-    glBegin(GL_QUADS);
-    glTexCoord2f(0, 0);
-    glVertex2f(0, 0);
-    glTexCoord2f(viewport[2], 0);
-    glVertex2f(frame_pixel_size_.width(), 0);
-    glTexCoord2f(viewport[2], viewport[3]);
-    glVertex2f(frame_pixel_size_.width(), frame_pixel_size_.height());
-    glTexCoord2f(0, viewport[3]);
-    glVertex2f(0, frame_pixel_size_.height());
-    glEnd();
-    glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0);
-    glDisable(GL_TEXTURE_RECTANGLE_ARB);
-
-    // Workaround for issue 158469. Issue a dummy draw call with
-    // io_surface_texture_ not bound to a texture, in order to shake all
-    // references to the IOSurface out of the driver.
-    glBegin(GL_TRIANGLES);
-    glEnd();
-  } else {
-    content::GpuDataManagerImpl::GetInstance()->AddLogMessage(
-        logging::LOG_ERROR,
-        "IOSurfaceLayer",
-        std::string("No texture to draw, clearing to white"));
+  if (!iosurface_->HasIOSurface() || context_->cgl_context() != glContext) {
     glClearColor(1, 1, 1, 1);
     glClear(GL_COLOR_BUFFER_BIT);
+    return;
   }
 
-  // Query the current GL renderer to send back to the GPU process.
-  {
-    CGLError cgl_error = CGLGetParameter(
-        glContext, kCGLCPCurrentRendererID, &cgl_renderer_id_);
-    if (cgl_error == kCGLNoError) {
-      cgl_renderer_id_ &= kCGLRendererIDMatchingMask;
-    } else {
-      content::GpuDataManagerImpl::GetInstance()->AddLogMessage(
-          logging::LOG_ERROR,
-          "IOSurfaceLayer",
-          std::string("CGLGetParameter for kCGLCPCurrentRendererID failed ") +
-              std::string("with CGL error ") + to_string(cgl_error));
-      cgl_renderer_id_ = 0;
-    }
-  }
-
-  // If we hit any errors, tell the client.
-  while (GLenum gl_error = glGetError()) {
-    content::GpuDataManagerImpl::GetInstance()->AddLogMessage(
-        logging::LOG_ERROR,
-        "IOSurfaceLayer",
-        std::string("Hit GL error ") + to_string(gl_error) +
-            std::string(" in drawInCGLContext"));
-    if (client_)
-      client_->IOSurfaceLayerHitError();
-  }
-
-  needs_display_ = false;
+  // The correct viewport to cover the layer will be set up by the caller.
+  // Transform this into a window size for DrawIOSurface, where it will be
+  // transformed back into this viewport.
+  GLint viewport[4];
+  glGetIntegerv(GL_VIEWPORT, viewport);
+  gfx::Rect window_rect(viewport[0], viewport[1], viewport[2], viewport[3]);
+  float window_scale_factor = 1.f;
+  if ([self respondsToSelector:(@selector(contentsScale))])
+    window_scale_factor = [self contentsScale];
+  window_rect = ToNearestRect(
+      gfx::ScaleRect(window_rect, 1.f/window_scale_factor));
+
+  bool draw_succeeded = iosurface_->DrawIOSurface(
+      context_, window_rect, window_scale_factor);
+
+  if (helper_)
+    helper_->DidDraw(draw_succeeded);
+
   [super drawInCGLContext:glContext
               pixelFormat:pixelFormat
              forLayerTime:timeInterval
               displayTime:timeStamp];
-
-  [self ackPendingFrame];
-}
-
-- (void)resetTextureAndPostDestroy {
-  if (!io_surface_texture_) {
-    DCHECK(!io_surface_texture_context_);
-    DCHECK(!io_surface_texture_io_surface_);
-    return;
-  }
-
-  // Post a task to clean up the texture on a clean stack.
-  base::MessageLoop::current()->PostTask(
-      FROM_HERE,
-      base::Bind(&DestroyTexture,
-                 io_surface_texture_context_,
-                 io_surface_texture_io_surface_,
-                 io_surface_texture_));
-
-  // Reset the texture state.
-  io_surface_texture_ = 0;
-  io_surface_texture_context_.reset();
-  io_surface_texture_io_surface_.reset();
-  cgl_renderer_id_ = 0;
 }
 
 @end