Restore r25049 (back out r25295) to isolate it as the cause of bug 20872.

TBR=pinkerton
BUG=20872
TEST=watch perf
Review URL: http://codereview.chromium.org/194008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@25296 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 8 insertions, 7 deletions

diff --git a/chrome/browser/cocoa/tab_strip_controller.mm b/chrome/browser/cocoa/tab_strip_controller.mm
index 69eae6d..2035cdc 100644
--- a/chrome/browser/cocoa/tab_strip_controller.mm
+++ b/chrome/browser/cocoa/tab_strip_controller.mm
@@ -419,8 +419,10 @@ static const float kUseFullAvailableWidth = -1.0;
         tabFrame.origin.x = offset;
       }
 
-      // Animate the tab in by putting it below the horizon.
-      if (newTab && visible && animate) {
+      // Animate the tab in by putting it below the horizon, but don't bother
+      // if we only have 1 tab.
+      BOOL shouldAnimate = animate && [tabContentsArray_ count] > 1;
+      if (newTab && visible && shouldAnimate) {
         [[tab view] setFrame:NSOffsetRect(tabFrame, 0, -NSHeight(tabFrame))];
       }
 
@@ -449,7 +451,8 @@ static const float kUseFullAvailableWidth = -1.0;
   }
 
   // Hide the new tab button if we're explicitly told to. It may already
-  // be hidden, doing it again doesn't hurt.
+  // be hidden, doing it again doesn't hurt. Otherwise position it
+  // appropriately, showing it if necessary.
   if (forceNewTabButtonHidden_) {
     [newTabButton_ setHidden:YES];
   } else {
@@ -461,10 +464,8 @@ static const float kUseFullAvailableWidth = -1.0;
     newTabNewFrame.origin.x = MAX(newTabNewFrame.origin.x,
                                   NSMaxX(placeholderFrame_)) +
                                       kNewTabButtonOffset;
-    if (i > 0 && [newTabButton_ isHidden]) {
-      id target = animate ? [newTabButton_ animator] : newTabButton_;
-      [target setHidden:NO];
-    }
+    if ([tabContentsArray_ count])
+      [newTabButton_ setHidden:NO];
 
     if (!NSEqualRects(newTabTargetFrame_, newTabNewFrame)) {
       [newTabButton_ setFrame:newTabNewFrame];