Ensure views have layers when they ought to. Note: performance on my MBP is...

Ensure views have layers when they ought to. Note: performance on my MBP is dramatically *worse* with layers. wtf

sources/PTYScrollView.m

@@ -146,10 +146,12 @@
 }
 - (void)boundsDidChangeNotification:(NSNotification *)notification {
+    if (!self.layer) {
+        return;
+    }
     if (!self.contentView.copiesOnScroll) {
         [self redrawSubviewsInRect:self.documentVisibleRect];
         [self redrawFloatingSubviews];
-        return;
     }
     NSRect newDocumentVisibleRect = self.documentVisibleRect;
     PTYClipView *clipView = (PTYClipView *)self.contentView;

sources/PTYSession.m

@@ -7706,4 +7706,8 @@ ITERM_WEAKLY_REFERENCEABLE
     return self.textview.excess;
 }
+- (void)sessionViewDidLayoutSubviews {
+    [self useTransparencyDidChange];
+}
+
 @end

sources/SessionView.h

@@ -117,6 +117,8 @@
 // Height of bottom of textview that should be obscured.
 - (CGFloat)sessionViewBottomMarginHeight;
+- (void)sessionViewDidLayoutSubviews;
+
 @end
 @interface SessionView : NSView <SessionTitleViewDelegate>

sources/SessionView.m

@@ -196,6 +196,8 @@ static NSDate* lastResizeDate_;
         }
     }
     _bottomMarginView.frame = self.frameForBottomMargin;
+
+    [_delegate sessionViewDidLayoutSubviews];
 }
 - (NSRect)frameForBottomMargin {

sources/iTermPreciseTimer.h

@@ -23,7 +23,7 @@ typedef struct {
     double m2;
 } iTermPreciseTimerStats;
-#define ENABLE_PRECISE_TIMERS 0
+#define ENABLE_PRECISE_TIMERS 1
 #if ENABLE_PRECISE_TIMERS
 void iTermPreciseTimerStart(iTermPreciseTimer *timer);