[Cleanup] Remove StringPrintf from global namespace

ui/compositor/layer_unittest.cc

 // Copyright (c) 2012 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 "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
@@ skipping 151 matching lines @@
   virtual ~TestLayerDelegate() {}
 
   void AddColor(SkColor color) {
     colors_.push_back(color);
   }
 
   const gfx::Size& paint_size() const { return paint_size_; }
   int color_index() const { return color_index_; }
 
   std::string ToScaleString() const {
-    return StringPrintf("%.1f %.1f", scale_x_, scale_y_);
+    return base::StringPrintf("%.1f %.1f", scale_x_, scale_y_);
   }
 
   float device_scale_factor() const {
     return device_scale_factor_;
   }
 
   // Overridden from LayerDelegate:
   virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE {
     gfx::ImageSkiaRep contents = canvas->ExtractImageRep();
     paint_size_ = gfx::Size(contents.pixel_width(), contents.pixel_height());
@@ skipping 1193 matching lines @@
   l1->SetOpacity(0.5f);
 
   // Change l1's cc::Layer.
   l1->SwitchCCLayerForTest();
 
   // Ensure that the opacity animation completed.
   EXPECT_FLOAT_EQ(l1->opacity(), 0.5f);
 }
 
 }  // namespace ui