Putting the findbar into a child window.

chrome/browser/cocoa/background_gradient_view.mm

Index: chrome/browser/cocoa/background_gradient_view.mm
===================================================================
--- chrome/browser/cocoa/background_gradient_view.mm	(revision 52179)
+++ chrome/browser/cocoa/background_gradient_view.mm	(working copy)
@@ -31,8 +31,12 @@
   [self setNeedsDisplay:YES];
 }
 
+- (BOOL)drawsAsKey {
+  return [[self window] isKeyWindow];
+}
+
 - (void)drawBackground {
-  BOOL isKey = [[self window] isKeyWindow];
+  BOOL isKey = [self drawsAsKey];
   ThemeProvider* themeProvider = [[self window] themeProvider];
   if (themeProvider) {
     NSColor* backgroundImageColor =
@@ -42,6 +46,8 @@
       NSRectFill([self bounds]);
     } else {
       CGFloat winHeight = NSHeight([[self window] frame]);
+      if ([[self window] parentWindow])
+        winHeight = NSHeight([[[self window] parentWindow] frame]);
       NSGradient* gradient = themeProvider->GetNSGradient(
           isKey ? BrowserThemeProvider::GRADIENT_TOOLBAR :
                   BrowserThemeProvider::GRADIENT_TOOLBAR_INACTIVE);
@@ -69,7 +75,7 @@
 }
 
 - (NSColor*)strokeColor {
-  BOOL isKey = [[self window] isKeyWindow];
+  BOOL isKey = [self drawsAsKey];
   ThemeProvider* themeProvider = [[self window] themeProvider];
   if (!themeProvider)
     return [NSColor blackColor];