Mac: Fix bad framerate when capturing tab

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 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/renderer_host/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 
@@ skipping 431 matching lines @@
   return scoped_ptr<ResizeLock>(lock);
 }
 
 DelegatedFrameHost* RenderWidgetHostViewMac::GetDelegatedFrameHost() const {
   return delegated_frame_host_.get();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // BrowserCompositorViewMacClient, public:
 
+bool RenderWidgetHostViewMac::BrowserCompositorViewShouldAckImmediately()
+    const {
+  // The logic for delegated and non-delegated rendering is the same.
+  return AcceleratedLayerShouldAckImmediately();
+}
+
 void RenderWidgetHostViewMac::BrowserCompositorViewFrameSwapped(
     const std::vector<ui::LatencyInfo>& all_latency_info) {
   if (!render_widget_host_)
     return;
   for (auto latency_info : all_latency_info) {
     latency_info.AddLatencyNumber(
         ui::INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT, 0, 0);
     render_widget_host_->FrameSwapped(latency_info);
   }
 }
@@ skipping 1057 matching lines @@
       std::string value =
           base::StringPrintf("window %s delegate %s controller %s",
               object_getClassName(window),
               object_getClassName([window delegate]),
               object_getClassName([window windowController]));
       base::debug::SetCrashKeyValue(kCrashKey, value);
     }
     return;
   }
 
-  // If the window is occluded, then this frame's display call may be severely
-  // throttled. This is a good thing, unless tab capture may be active,
-  // because the broadcast will be inappropriately throttled.
-  // http://crbug.com/350410
-  NSWindow* window = [cocoa_view_ window];
-  if (window && [window respondsToSelector:@selector(occlusionState)]) {
-    bool window_is_occluded =
-        !([window occlusionState] & NSWindowOcclusionStateVisible);
-    // Note that we aggressively ack even if this particular frame is not being
-    // captured.
-    if (window_is_occluded && frame_subscriber_)
-      scoped_ack.Reset();
-  }
-
   // If we reach here, then the frame will be displayed by a future draw
   // call, so don't make the callback.
   ignore_result(scoped_ack.Release());
   DCHECK(compositing_iosurface_layer_);
   [compositing_iosurface_layer_ gotNewFrame];
 
   // Try to finish previous copy requests after draw to get better pipelining.
   if (compositing_iosurface_)
     compositing_iosurface_->CheckIfAllCopiesAreFinished(false);
 
@@ skipping 684 matching lines @@
   }
 }
 
 SkColorType RenderWidgetHostViewMac::PreferredReadbackFormat() {
   return kN32_SkColorType;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // CompositingIOSurfaceLayerClient, public:
 
+bool RenderWidgetHostViewMac::AcceleratedLayerShouldAckImmediately() const {
+  // If vsync is disabled, then always draw and ack frames immediately.
+  static bool is_vsync_disabled =
+      CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableGpuVsync);
+  if (is_vsync_disabled)
+    return true;
+
+  // If the window is occluded, then this frame's display call may be severely
+  // throttled. This is a good thing, unless tab capture may be active, because
+  // the broadcast will be inappropriately throttled.
+  // http://crbug.com/350410
+
+  // If tab capture isn't active then only ack frames when we draw them.
+  if (delegated_frame_host_) {
+    if (!delegated_frame_host_->HasFrameSubscriber())
+      return false;
+  } else {
+    if (!frame_subscriber_)
+      return false;
+  }
+
+  NSWindow* window = [cocoa_view_ window];
+  // If the view isn't even in the heirarchy then frames will never be drawn,
+  // so ack them immediately.
+  if (!window)
+    return true;
+
+  // Check the window occlusion API.
+  if ([window respondsToSelector:@selector(occlusionState)]) {
+    if ([window occlusionState] & NSWindowOcclusionStateVisible) {
+      // If the window is visible then it is safe to wait until frames are
+      // drawn to ack them.
+      return false;
+    } else {
+      // If the window is occluded then frames may never be drawn, so ack them
+      // immediately.
+      return true;
+    }
+  }
+
+  // If the window occlusion API is not present then ack frames when we draw
+  // them.
+  return false;
+}
+
 void RenderWidgetHostViewMac::AcceleratedLayerDidDrawFrame(bool succeeded) {
   if (!render_widget_host_)
     return;
 
   SendPendingLatencyInfoToHost();
   SendPendingSwapAck();
   if (!succeeded)
     GotAcceleratedCompositingError();
 }
 
@@ skipping 1693 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end