Mac: Well-behaved accelerated plugins, actual fix

chrome/browser/cocoa/chrome_browser_window.mm

Index: chrome/browser/cocoa/chrome_browser_window.mm
diff --git a/chrome/browser/cocoa/chrome_browser_window.mm b/chrome/browser/cocoa/chrome_browser_window.mm
index 35aae1aec454921368e92d926855a79b8f45fec9..25826a390277c25709e84398ecf02f4ad5e15b16 100644
--- a/chrome/browser/cocoa/chrome_browser_window.mm
+++ b/chrome/browser/cocoa/chrome_browser_window.mm
@@ -243,6 +243,24 @@ namespace {
   }
 }
 
+- (void)underlaySurfaceAdded {
+  DCHECK_GE(underlaySurfaceCount_, 0);
+  ++underlaySurfaceCount_;
+
+  // We're having the OpenGL surface render under the window, so the window
+  // needs to be not opaque.
+  if (underlaySurfaceCount_ == 1)
+    [self setOpaque:NO];
+}
+
+- (void)underlaySurfaceRemoved {
+  --underlaySurfaceCount_;
+  DCHECK_GE(underlaySurfaceCount_, 0);
+
+  if (underlaySurfaceCount_ == 0)
+    [self setOpaque:YES];
+}
+
 - (void)windowMainStatusChanged {
   [closeButton_ setNeedsDisplay];
   [zoomButton_ setNeedsDisplay];