Fix flipped views on Mac

content/browser/compositor/browser_compositor_view_private_mac.mm

 // Copyright 2014 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/browser_compositor_view_private_mac.h"
 
 #include "base/debug/trace_event.h"
 #include "content/browser/compositor/gpu_process_transport_factory.h"
 #include "content/browser/renderer_host/compositing_iosurface_context_mac.h"
 #include "content/browser/renderer_host/compositing_iosurface_mac.h"
 #include "content/browser/renderer_host/software_layer_mac.h"
 #include "content/public/browser/context_factory.h"
 #include "ui/base/cocoa/animation_utils.h"
 #include "ui/gl/scoped_cgl.h"
 
 ////////////////////////////////////////////////////////////////////////////////
 // BrowserCompositorViewCocoa
 
 @implementation BrowserCompositorViewCocoa : NSView
 
 - (id)init {
   if (self = [super init]) {
     accelerated_layer_output_surface_id_ = 0;
     client_ = NULL;
     helper_.reset(new content::BrowserCompositorViewCocoaHelper(self));
 
     // Disable the fade-in animation as the layer and view are added.
     ScopedCAActionDisabler disabler;
 
-    // Make this view host a transparent layer.
-    background_layer_.reset([[CALayer alloc] init]);
-    [background_layer_ setContentsGravity:kCAGravityTopLeft];
-    [self setLayer:background_layer_];
-    [self setWantsLayer:YES];
+    // Add a flipped transparent layer as a child, so that we don't need to
+    // fiddle with the position of sub-layers -- they will always be at the
+    // origin.
+    flipped_layer_.reset([[CALayer alloc] init]);
+    [flipped_layer_ setGeometryFlipped:YES];
+    [flipped_layer_ setAnchorPoint:CGPointMake(0, 0)];
+    [flipped_layer_
+        setAutoresizingMask:kCALayerWidthSizable|kCALayerHeightSizable];
 
     compositor_.reset(new ui::Compositor(self, content::GetContextFactory()));
   }
   return self;
 }
 
 - (void)setClient:(content::BrowserCompositorViewMacClient*)client {
   // Disable the fade-out as layers are removed.
   ScopedCAActionDisabler disabler;
-  [self removeFromSuperview];
 
   // Reset all state.
+  [flipped_layer_ removeFromSuperlayer];
   [accelerated_layer_ removeFromSuperlayer];
   [accelerated_layer_ resetClient];
   accelerated_layer_.reset();
   accelerated_layer_output_surface_id_ = 0;
   [software_layer_ removeFromSuperlayer];
   software_layer_.reset();
   compositor_->SetScaleAndSize(1.0, gfx::Size(0, 0));
 
   client_ = client;
   if (client_) {
     DCHECK(compositor_);
     compositor_->SetRootLayer(client_->BrowserCompositorRootLayer());
-    [client_->BrowserCompositorSuperview() addSubview:self];
+    CALayer* background_layer = [client_->BrowserCompositorSuperview() layer];
+    DCHECK(background_layer);
+    [flipped_layer_ setBounds:[background_layer bounds]];
+    [background_layer addSublayer:flipped_layer_];
   } else {
     compositor_->SetRootLayer(NULL);
   }
 }
 
 - (void)destroyCompositor {
   DCHECK(!client_);
   compositor_.reset();
 }
 
@@ skipping 34 matching lines @@
   // If there is not a layer for accelerated frames, create one.
   if (!accelerated_layer_) {
     // Disable the fade-in animation as the layer is added.
     ScopedCAActionDisabler disabler;
     scoped_refptr<content::CompositingIOSurfaceMac> iosurface =
         content::CompositingIOSurfaceMac::Create();
     accelerated_layer_.reset([[CompositingIOSurfaceLayer alloc]
         initWithIOSurface:iosurface
           withScaleFactor:scale_factor
                withClient:helper_.get()]);
-    [[self layer] addSublayer:accelerated_layer_];
+    [flipped_layer_ addSublayer:accelerated_layer_];
   }
 
   {
     bool result = true;
     gfx::ScopedCGLSetCurrentContext scoped_set_current_context(
         [accelerated_layer_ context]->cgl_context());
     result = [accelerated_layer_ iosurface]->SetIOSurfaceWithContextCurrent(
         [accelerated_layer_ context], surface_handle, pixel_size, scale_factor);
     if (!result)
       LOG(ERROR) << "Failed SetIOSurface on CompositingIOSurfaceMac";
@@ skipping 31 matching lines @@
          withScaleFactor:(float)scale_factor
               withCanvas:(SkCanvas*)canvas {
   if (!frame_data || !canvas)
     return;
 
   // If there is not a layer for software frames, create one.
   if (!software_layer_) {
     // Disable the fade-in animation as the layer is added.
     ScopedCAActionDisabler disabler;
     software_layer_.reset([[SoftwareLayer alloc] init]);
-    [[self layer] addSublayer:software_layer_];
+    [flipped_layer_ addSublayer:software_layer_];
   }
 
   SkImageInfo info;
   size_t row_bytes;
   const void* pixels = canvas->peekPixels(&info, &row_bytes);
   [software_layer_ setContentsToData:pixels
                         withRowBytes:row_bytes
                        withPixelSize:gfx::Size(info.fWidth, info.fHeight)
                      withScaleFactor:scale_factor];
 
@@ skipping 35 matching lines @@
 
 void BrowserCompositorViewCocoaHelper::AcceleratedLayerDidDrawFrame(
     bool succeeded) {
   [view_ layerDidDrawFrame];
   if (!succeeded)
     [view_ gotAcceleratedLayerError];
 }
 
 }