Change snasphotting API to take in a bounds Rect

chrome/browser/ui/window_snapshot/window_snapshot_mac.mm

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/window_snapshot/window_snapshot.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/logging.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/memory/scoped_nsobject.h"
 #include "ui/gfx/rect.h"
 
 namespace browser {
 
-gfx::Rect GrabWindowSnapshot(gfx::NativeWindow window,
-    std::vector<unsigned char>* png_representation) {
+bool GrabWindowSnapshot(gfx::NativeWindow window,
+    std::vector<unsigned char>* png_representation,
+    const gfx::Rect& snapshot_bounds) {
+  NSScreen* screen = [[NSScreen screens] objectAtIndex:0];
+  gfx::Rect screen_bounds = gfx::Rect(NSRectToCGRect([screen frame]));
+  gfx::Rect window_bounds = gfx::Rect(NSRectToCGRect([window frame]));
+
+  // Flip window coordinates based on the primary screen.
+  window_bounds.set_y(
+      screen_bounds.height() - window_bounds.y() - window_bounds.height());
+
+  // Convert snapshot bounds relative to window into bounds relative to
+  // screen.
+  gfx::Rect screen_snapshot_bounds = gfx::Rect(
+      window_bounds.origin().Add(snapshot_bounds.origin()),
+      snapshot_bounds.size());
+
+  DCHECK_LE(screen_snapshot_bounds.right(), window_bounds.right());
+  DCHECK_LE(screen_snapshot_bounds.bottom(), window_bounds.bottom());
+
   png_representation->clear();
 
   // Make sure to grab the "window frame" view so we get current tab +
   // tabstrip.
   NSView* view = [[window contentView] superview];
   base::mac::ScopedCFTypeRef<CGImageRef> windowSnapshot(CGWindowListCreateImage(
-      CGRectNull, kCGWindowListOptionIncludingWindow,
+      screen_snapshot_bounds.ToCGRect(), kCGWindowListOptionIncludingWindow,
       [[view window] windowNumber], kCGWindowImageBoundsIgnoreFraming));
   if (CGImageGetWidth(windowSnapshot) <= 0)
-    return gfx::Rect();
+    return false;
 
   scoped_nsobject<NSBitmapImageRep> rep(
       [[NSBitmapImageRep alloc] initWithCGImage:windowSnapshot]);
   NSData* data = [rep representationUsingType:NSPNGFileType properties:nil];
   const unsigned char* buf = static_cast<const unsigned char*>([data bytes]);
   NSUInteger length = [data length];
   if (buf == NULL || length == 0)
-    return gfx::Rect();
+    return false;
 
   png_representation->assign(buf, buf + length);
   DCHECK(!png_representation->empty());
 
-  return gfx::Rect(static_cast<int>([rep pixelsWide]),
-                   static_cast<int>([rep pixelsHigh]));
+  return true;
 }
 
 }  // namespace browser