fix mac frame-rate regression for non-threaded GPU compositing

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"
 
 #include <QuartzCore/QuartzCore.h>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 150 matching lines @@
   return YES;
 }
 
 @end
 
 namespace {
 
 // Maximum number of characters we allow in a tooltip.
 const size_t kMaxTooltipLength = 1024;
 
-// Invalidation NSRect to trigger a drawRect on BuffersSwapped.
-const NSRect kGpuSwapBuffersDirtyRect = { {0, 0}, {1, 1} };
-
 // TODO(suzhe): Upstream this function.
 WebKit::WebColor WebColorFromNSColor(NSColor *color) {
   CGFloat r, g, b, a;
   [color getRed:&r green:&g blue:&b alpha:&a];
 
   return
       std::max(0, std::min(static_cast<int>(lroundf(255.0f * a)), 255)) << 24 |
       std::max(0, std::min(static_cast<int>(lroundf(255.0f * r)), 255)) << 16 |
       std::max(0, std::min(static_cast<int>(lroundf(255.0f * g)), 255)) << 8  |
       std::max(0, std::min(static_cast<int>(lroundf(255.0f * b)), 255));
@@ skipping 801 matching lines @@
   gfx::Size window_size(NSSizeToCGSize([cocoa_view_ frame].size));
   if (window_size.IsEmpty()) {
     // setNeedsDisplay will never display and we'll never ack if the window is
     // empty, so ack now and don't bother calling setNeedsDisplay below.
     return true;
   }
 
   // No need to draw the surface if we are inside a drawRect. It will be done
   // later.
   if (!about_to_validate_and_paint_) {
-    // Trigger a drawRect, but don't invalidate the whole window because it
-    // is expensive to clear it with transparency to expose the GL underneath.
-    [cocoa_view_ setNeedsDisplayInRect:kGpuSwapBuffersDirtyRect];
-
-    // While resizing, OSX fails to call drawRect on the NSView unless the
-    // window size has changed. That means we won't see animations update if the
-    // user has the mouse button held down, but is not currently changing the
-    // size of the window. To work around that, display here while resizing.
-    // Also, OSX will never call drawRect faster than vsync rate, so if
-    // disable-gpu-vsync is set, we need to display now.
-    if (compositing_iosurface_->is_vsync_disabled() ||
-        [cocoa_view_ inLiveResize]) {
-      [cocoa_view_ displayIfNeeded];
-    }
+    compositing_iosurface_->DrawIOSurface(cocoa_view_,
+                                          ScaleFactor(cocoa_view_));
   }
-  return false;
+  return true;
 }
 
 void RenderWidgetHostViewMac::AckPendingSwapBuffers() {
   TRACE_EVENT0("browser", "RenderWidgetHostViewMac::AckPendingSwapBuffers");
   while (!pending_swap_buffers_acks_.empty()) {
     if (pending_swap_buffers_acks_.front().first != 0) {
       RenderWidgetHostImpl::AcknowledgeBufferPresent(
           pending_swap_buffers_acks_.front().first,
           pending_swap_buffers_acks_.front().second,
           0);
@@ skipping 1134 matching lines @@
   // blit the IOSurface below.
   renderWidgetHostView_->about_to_validate_and_paint_ = true;
   BackingStoreMac* backingStore = static_cast<BackingStoreMac*>(
       renderWidgetHostView_->render_widget_host_->GetBackingStore(true));
   renderWidgetHostView_->about_to_validate_and_paint_ = false;
 
   const gfx::Rect damagedRect([self flipNSRectToRect:dirtyRect]);
 
   if (renderWidgetHostView_->last_frame_was_accelerated_ &&
       renderWidgetHostView_->compositing_iosurface_.get()) {
-    bool is_swap_without_dirty =
-        (dirtyRect.origin.x == kGpuSwapBuffersDirtyRect.origin.x &&
-         dirtyRect.origin.y == kGpuSwapBuffersDirtyRect.origin.y &&
-         dirtyRect.size.width == kGpuSwapBuffersDirtyRect.size.width &&
-         dirtyRect.size.height == kGpuSwapBuffersDirtyRect.size.height);
-    if (!is_swap_without_dirty) {
+    {
       TRACE_EVENT2("gpu", "NSRectFill clear", "w", damagedRect.width(),
                    "h", damagedRect.height());
       // Draw transparency to expose the GL underlay. NSRectFill is extremely
       // slow (15ms for a window on a fast MacPro), so this is only done when
       // it's a real invalidation from window damage (not when a BuffersSwapped
       // was received). Note that even a 1x1 NSRectFill can take many
       // milliseconds sometimes (!) so this is skipped completely for drawRects
       // that are triggered by BuffersSwapped messages.
       [[NSColor clearColor] set];
       NSRectFill(dirtyRect);
     }
 
     // TODO(thakis): Register for backing scale factor change events and pass
     // that on.
     renderWidgetHostView_->compositing_iosurface_->DrawIOSurface(
         self, ScaleFactor(self));
-    // For latency_tests.cc:
-    UNSHIPPED_TRACE_EVENT_INSTANT0("test_gpu", "CompositorSwapBuffersComplete");
-    renderWidgetHostView_->AckPendingSwapBuffers();
     return;
   }
 
   if (backingStore) {
     // Note: All coordinates are in view units, not pixels.
     gfx::Rect bitmapRect(0, 0,
                          backingStore->size().width(),
                          backingStore->size().height());
 
     // Specify the proper y offset to ensure that the view is rooted to the
@@ skipping 1004 matching lines @@
   if (!string) return NO;
 
   // If the user is currently using an IME, confirm the IME input,
   // and then insert the text from the service, the same as TextEdit and Safari.
   [self confirmComposition];
   [self insertText:string];
   return YES;
 }
 
 @end