Make tab/tabstrip high density compatible
added ImageSkiaOperations and replaced Bitmap with ImageSkiaRep/ImagSkia.

BUG=122992
TEST=manual

Review URL: https://chromiumcodereview.appspot.com/10704113

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@145976 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/ui/base/ui_base_switches.cc b/ui/base/ui_base_switches.cc
index b4c1ca3..33cff9f 100644
--- a/ui/base/ui_base_switches.cc
+++ b/ui/base/ui_base_switches.cc
@@ -6,6 +6,11 @@
 
 namespace switches {
 
+// Whether or not ImageSkiaOperations methods can scale one of images
+// if they don't have the same scale factor.
+const char kDisableScalingInImageSkiaOperations[] =
+    "disable-scaling-in-image-skia-operations";
+
 // Let text glyphs have X-positions that aren't snapped to the pixel grid.
 const char kEnableTextSubpixelPositioning[] =
     "enable-text-subpixel-positioning";