Add a path to use CALayers to display content

Add the flag --use-core-animation to enable this path.

Make the RenderWidgetHostViewCocoa layer-backed, and add a
default white layer.

Add a CALayer, softwareLayer_ to draw into when the accelerated
path is disabled. Update the software draw methods to use the CG
calls (this changes the non-CA path as well, but should be equivalent
to previous behavior).

If accelerated compositing is enabled, then add CAOpenGLLayer to
draw accelerated frames (frames using IOSurfaces). If we receive a
software frame, then delete this layer (and the software layer will
appear below it).

This still has a number of issues to resolve before enabling, including
- corrupted bookmark bars
- increased CPU usage (3.5%->5% without compositing, 7%->10% with)
- increased startup time

BUG=245900
NOTRY=True

Review URL: https://chromiumcodereview.appspot.com/16189012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@204841 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 6 insertions, 0 deletions

diff --git a/base/mac/sdk_forward_declarations.h b/base/mac/sdk_forward_declarations.h
index 387400d..4b74c36 100644
--- a/base/mac/sdk_forward_declarations.h
+++ b/base/mac/sdk_forward_declarations.h
@@ -43,6 +43,12 @@ typedef NSUInteger NSEventSwipeTrackingOptions;
 - (BOOL)isDirectionInvertedFromDevice;
 
 @end
+
+@interface CALayer (LionAPI)
+- (CGFloat)contentsScale;
+- (void)setContentsScale:(CGFloat)contentsScale;
+@end
+
 #endif  // MAC_OS_X_VERSION_10_7
 
 #endif  // BASE_MAC_SDK_FORWARD_DECLARATIONS_H_