Revert of Mac Overlays: Add GPU back-pressure

content/common/gpu/image_transport_surface_overlay_mac.mm

Index: content/common/gpu/image_transport_surface_overlay_mac.mm
diff --git a/content/common/gpu/image_transport_surface_overlay_mac.mm b/content/common/gpu/image_transport_surface_overlay_mac.mm
index 213f0455b5e88763ff9a0438845403f4f2b9b9e9..1a528333529330c9b8872a8f6c71be59970c170b 100644
--- a/content/common/gpu/image_transport_surface_overlay_mac.mm
+++ b/content/common/gpu/image_transport_surface_overlay_mac.mm
@@ -4,92 +4,27 @@
 
 #include "content/common/gpu/image_transport_surface_overlay_mac.h"
 
-#include <IOSurface/IOSurface.h>
-#include <OpenGL/GL.h>
+#include <OpenGL/gl.h>
 
-// This type consistently causes problem on Mac, and needs to be dealt with
-// in a systemic way.
-// http://crbug.com/517208
-#ifndef GL_OES_EGL_image
-typedef void* GLeglImageOES;
-#endif
-
-#include "base/mac/scoped_cftyperef.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "ui/accelerated_widget_mac/surface_handle_types.h"
 #include "ui/base/cocoa/animation_utils.h"
 #include "ui/base/cocoa/remote_layer_api.h"
 #include "ui/gfx/geometry/dip_util.h"
-#include "ui/gl/gl_fence_apple.h"
 #include "ui/gl/gl_image_io_surface.h"
-#include "ui/gl/scoped_api.h"
-#include "ui/gl/scoped_cgl.h"
-
-namespace {
-
-// Don't let a frame draw until 5% of the way through the next vsync interval
-// after the call to SwapBuffers. This slight offset is to ensure that skew
-// doesn't result in the frame being presented to the previous vsync interval.
-
-const double kVSyncIntervalFractionForEarliestDisplay = 0.05;
-// Target 50% of the way through the next vsync interval. Empirically, it has
-// been determined to be a good target for smooth animation.
-const double kVSyncIntervalFractionForDisplayCallback = 0.5;
-
-// If a frame takes more than 1/4th of a second for its fence to finish, just
-// pretend that the frame is ready to draw.
-const double kMaximumDelayWaitingForFenceInSeconds = 0.25;
-
-void CheckGLErrors(const char* msg) {
-  GLenum gl_error;
-  while ((gl_error = glGetError()) != GL_NO_ERROR) {
-    LOG(ERROR) << "OpenGL error hit " << msg << ": " << gl_error;
-  }
-}
-
-}  // namespace
-
-@interface CALayer(Private)
--(void)setContentsChanged;
-@end
 
 namespace content {
-
-class ImageTransportSurfaceOverlayMac::PendingSwap {
- public:
-  PendingSwap() : scale_factor(1) {}
-  ~PendingSwap() { DCHECK(!fence); }
-
-  gfx::Size pixel_size;
-  float scale_factor;
-  std::vector<ui::LatencyInfo> latency_info;
-
-  // The IOSurface with new content for this swap.
-  base::ScopedCFTypeRef<IOSurfaceRef> io_surface;
-
-  // A fence object, and the CGL context it was issued in.
-  base::ScopedTypeRef<CGLContextObj> cgl_context;
-  scoped_ptr<gfx::GLFenceAPPLE> fence;
-
-  // The earliest time that this frame may be drawn. A frame is not allowed
-  // to draw until a fraction of the way through the vsync interval after its
-  // This extra latency is to allow wiggle-room for smoothness.
-  base::TimeTicks earliest_allowed_draw_time;
-  // After this time, always draw the frame, no matter what its fence says. This
-  // is to prevent GL bugs from locking the compositor forever.
-  base::TimeTicks latest_allowed_draw_time;
-};
 
 ImageTransportSurfaceOverlayMac::ImageTransportSurfaceOverlayMac(
     GpuChannelManager* manager,
     GpuCommandBufferStub* stub,
     gfx::PluginWindowHandle handle)
-    : scale_factor_(1), pending_overlay_image_(nullptr),
-      has_pending_callback_(false), weak_factory_(this) {
+    : scale_factor_(1), pending_overlay_image_(nullptr) {
   helper_.reset(new ImageTransportHelper(this, manager, stub, handle));
 }
 
 ImageTransportSurfaceOverlayMac::~ImageTransportSurfaceOverlayMac() {
+  gfx::GLImageIOSurface::SetLayerForWidget(widget_, nil);
 }
 
 bool ImageTransportSurfaceOverlayMac::Initialize() {
@@ -102,225 +37,61 @@
   ca_context_.reset(
       [[CAContext contextWithCGSConnection:connection_id options:@{}] retain]);
   layer_.reset([[CALayer alloc] init]);
-  [layer_ setGeometryFlipped:YES];
-  [layer_ setOpaque:YES];
   [ca_context_ setLayer:layer_];
+
+  // Register the CALayer so that it can be picked up in GLImageIOSurface.
+  static intptr_t previous_widget = 0;
+  previous_widget += 1;
+  widget_ = reinterpret_cast<gfx::AcceleratedWidget>(previous_widget);
+  gfx::GLImageIOSurface::SetLayerForWidget(widget_, layer_);
+
   return true;
 }
 
-void ImageTransportSurfaceOverlayMac::Destroy() {
-  FinishAllPendingSwaps();
-}
+void ImageTransportSurfaceOverlayMac::Destroy() {}
 
 bool ImageTransportSurfaceOverlayMac::IsOffscreen() {
   return false;
 }
 
-gfx::SwapResult ImageTransportSurfaceOverlayMac::SwapBuffersInternal(
-    const gfx::Rect& pixel_damage_rect) {
-  TRACE_EVENT0("gpu", "ImageTransportSurfaceOverlayMac::SwapBuffersInternal");
+gfx::SwapResult ImageTransportSurfaceOverlayMac::SwapBuffers() {
+  TRACE_EVENT0("gpu", "ImageTransportSurfaceOverlayMac::SwapBuffers");
 
-  // Use the same concept of 'now' for the entire function. The duration of
-  // this function only affect the result if this function lasts across a vsync
-  // boundary, in which case smooth animation is out the window anyway.
-  const base::TimeTicks now = base::TimeTicks::Now();
-
-  // If the previous swap is ready to display, do it before flushing the
-  // new swap. It is desirable to always be hitting this path when trying to
-  // animate smoothly with vsync.
-  if (!pending_swaps_.empty()) {
-    if (IsFirstPendingSwapReadyToDisplay(now))
-      DisplayFirstPendingSwapImmediately();
+  // A flush is required to ensure that all content appears in the layer.
+  {
+    TRACE_EVENT0("gpu", "ImageTransportSurfaceOverlayMac::glFlush");
+    glFlush();
   }
-
-  // The remainder of the function will populate the PendingSwap structure and
-  // then enqueue it.
-  linked_ptr<PendingSwap> new_swap(new PendingSwap);
-  new_swap->pixel_size = pixel_size_;
-  new_swap->scale_factor = scale_factor_;
-  new_swap->latency_info.swap(latency_info_);
 
   // There should exist only one overlay image, and it should cover the whole
   // surface.
   DCHECK(pending_overlay_image_);
   if (pending_overlay_image_) {
-    gfx::GLImageIOSurface* pending_overlay_image_io_surface =
-        static_cast<gfx::GLImageIOSurface*>(pending_overlay_image_);
-    new_swap->io_surface = pending_overlay_image_io_surface->io_surface();
+    TRACE_EVENT0("gpu", "ImageTransportSurfaceOverlayMac::setContents");
+    ScopedCAActionDisabler disabler;
+    gfx::Rect dip_bounds = gfx::ConvertRectToDIP(
+        scale_factor_, gfx::Rect(pixel_size_));
+    gfx::RectF crop_rect(0, 0, 1, 1);
+    pending_overlay_image_->ScheduleOverlayPlane(
+        widget_, 0, gfx::OVERLAY_TRANSFORM_NONE, dip_bounds, crop_rect);
     pending_overlay_image_ = nullptr;
   }
 
-  // A flush is required to ensure that all content appears in the layer.
-  {
-    gfx::ScopedSetGLToRealGLApi scoped_set_gl_api;
-    TRACE_EVENT1("gpu", "ImageTransportSurfaceOverlayMac::glFlush", "surface",
-                 new_swap->io_surface.get());
-    CheckGLErrors("before flushing frame");
-    new_swap->cgl_context.reset(CGLGetCurrentContext(),
-                                base::scoped_policy::RETAIN);
-    new_swap->fence.reset(new gfx::GLFenceAPPLE);
-    CheckGLErrors("while flushing frame");
-  }
-
-  // Compute the deadlines for drawing this frame.
-  if (display_link_mac_) {
-    new_swap->earliest_allowed_draw_time =
-        display_link_mac_->GetNextVSyncTimeAfter(
-            now, kVSyncIntervalFractionForEarliestDisplay);
-    new_swap->latest_allowed_draw_time = now +
-        base::TimeDelta::FromSecondsD(kMaximumDelayWaitingForFenceInSeconds);
-  } else {
-    // If we have no display link (because vsync is disabled or because we have
-    // not received display parameters yet), immediately attempt to display the
-    // surface.
-    new_swap->earliest_allowed_draw_time = now;
-    new_swap->latest_allowed_draw_time = now;
-  }
-
-  pending_swaps_.push_back(new_swap);
-  PostCheckPendingSwapsCallbackIfNeeded(now);
-  return gfx::SwapResult::SWAP_ACK;
-}
-
-bool ImageTransportSurfaceOverlayMac::IsFirstPendingSwapReadyToDisplay(
-    const base::TimeTicks& now) {
-  DCHECK(!pending_swaps_.empty());
-  linked_ptr<PendingSwap> swap = pending_swaps_.front();
-
-  // If more that a certain amount of time has passed since the swap,
-  // unconditionally continue.
-  if (now > swap->latest_allowed_draw_time)
-    return true;
-
-  // Frames are disallowed from drawing until the vsync interval after their
-  // swap is issued.
-  if (now < swap->earliest_allowed_draw_time)
-    return false;
-
-  // If there is no fence then this is either for immediate display, or the
-  // fence was aready successfully checked and deleted.
-  if (!swap->fence)
-    return true;
-
-  // Check if the pending work has finished (and early-out if it is not, and
-  // this is not forced).
-  bool has_completed = false;
-  {
-    gfx::ScopedSetGLToRealGLApi scoped_set_gl_api;
-    gfx::ScopedCGLSetCurrentContext scoped_set_current(swap->cgl_context);
-
-    CheckGLErrors("before testing fence");
-    has_completed= swap->fence->HasCompleted();
-    CheckGLErrors("after testing fence");
-    if (has_completed) {
-      swap->fence.reset();
-      CheckGLErrors("while deleting fence");
-    }
-  }
-  return has_completed;
-}
-
-void ImageTransportSurfaceOverlayMac::DisplayFirstPendingSwapImmediately() {
-  TRACE_EVENT0("gpu",
-      "ImageTransportSurfaceOverlayMac::DisplayFirstPendingSwapImmediately");
-  DCHECK(!pending_swaps_.empty());
-  linked_ptr<PendingSwap> swap = pending_swaps_.front();
-
-  // If there is a fence for this object, delete it.
-  if (swap->fence) {
-    gfx::ScopedSetGLToRealGLApi scoped_set_gl_api;
-    gfx::ScopedCGLSetCurrentContext scoped_set_current(swap->cgl_context);
-
-    CheckGLErrors("before deleting active fence");
-    swap->fence.reset();
-    CheckGLErrors("while deleting active fence");
-  }
-
-  // Update the CALayer hierarchy.
-  {
-    TRACE_EVENT1("gpu", "ImageTransportSurfaceOverlayMac::setContents",
-                 "surface", swap->io_surface.get());
-    ScopedCAActionDisabler disabler;
-
-    id new_contents = static_cast<id>(swap->io_surface.get());
-    [layer_ setContents:new_contents];
-
-    CGRect new_frame = gfx::ConvertRectToDIP(
-        swap->scale_factor, gfx::Rect(swap->pixel_size)).ToCGRect();
-    if (!CGRectEqualToRect([layer_ frame], new_frame))
-      [layer_ setFrame:new_frame];
-  }
-
-  // Send acknowledgement to the browser.
   GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params;
   params.surface_handle =
       ui::SurfaceHandleFromCAContextID([ca_context_ contextId]);
   params.size = pixel_size_;
   params.scale_factor = scale_factor_;
-  params.latency_info.swap(swap->latency_info);
+  params.latency_info.swap(latency_info_);
   helper_->SendAcceleratedSurfaceBuffersSwapped(params);
-
-  // Remove this from the queue, and reset any callback timers.
-  pending_swaps_.pop_front();
-}
-
-void ImageTransportSurfaceOverlayMac::FinishAllPendingSwaps() {
-  TRACE_EVENT0("gpu", "ImageTransportSurfaceOverlayMac::FinishAllPendingSwaps");
-  while (!pending_swaps_.empty())
-    DisplayFirstPendingSwapImmediately();
-}
-
-void ImageTransportSurfaceOverlayMac::CheckPendingSwapsCallback() {
-  TRACE_EVENT0("gpu",
-      "ImageTransportSurfaceOverlayMac::CheckPendingSwapsCallback");
-
-  DCHECK(has_pending_callback_);
-  has_pending_callback_ = false;
-
-  if (pending_swaps_.empty())
-    return;
-
-  const base::TimeTicks now = base::TimeTicks::Now();
-  if (IsFirstPendingSwapReadyToDisplay(now))
-    DisplayFirstPendingSwapImmediately();
-  PostCheckPendingSwapsCallbackIfNeeded(now);
-}
-
-void ImageTransportSurfaceOverlayMac::PostCheckPendingSwapsCallbackIfNeeded(
-    const base::TimeTicks& now) {
-  TRACE_EVENT0("gpu",
-      "ImageTransportSurfaceOverlayMac::PostCheckPendingSwapsCallbackIfNeeded");
-
-  if (has_pending_callback_)
-    return;
-  if (pending_swaps_.empty())
-    return;
-
-  base::TimeTicks target;
-  if (display_link_mac_) {
-    target = display_link_mac_->GetNextVSyncTimeAfter(
-          now, kVSyncIntervalFractionForDisplayCallback);
-  } else {
-    target = now;
-  }
-  base::TimeDelta delay = target - now;
-
-  base::MessageLoop::current()->PostDelayedTask(
-      FROM_HERE,
-      base::Bind(&ImageTransportSurfaceOverlayMac::CheckPendingSwapsCallback,
-                     weak_factory_.GetWeakPtr()), delay);
-  has_pending_callback_ = true;
-}
-
-gfx::SwapResult ImageTransportSurfaceOverlayMac::SwapBuffers() {
-  return SwapBuffersInternal(gfx::Rect(pixel_size_));
+  return gfx::SwapResult::SWAP_ACK;
 }
 
 gfx::SwapResult ImageTransportSurfaceOverlayMac::PostSubBuffer(int x,
                                                                int y,
                                                                int width,
                                                                int height) {
-  return SwapBuffersInternal(gfx::Rect(x, y, width, height));
+  return SwapBuffers();
 }
 
 bool ImageTransportSurfaceOverlayMac::SupportsPostSubBuffer() {
@@ -358,18 +129,10 @@
 }
 
 void ImageTransportSurfaceOverlayMac::OnBufferPresented(
-    const AcceleratedSurfaceMsg_BufferPresented_Params& params) {
-  if (display_link_mac_ &&
-      display_link_mac_->display_id() == params.display_id_for_vsync)
-    return;
-  display_link_mac_ = ui::DisplayLinkMac::GetForDisplay(
-      params.display_id_for_vsync);
-}
+    const AcceleratedSurfaceMsg_BufferPresented_Params& params) {}
 
 void ImageTransportSurfaceOverlayMac::OnResize(gfx::Size pixel_size,
                                                float scale_factor) {
-  // Flush through any pending frames.
-  FinishAllPendingSwaps();
   pixel_size_ = pixel_size;
   scale_factor_ = scale_factor;
 }