Fix gcc 4.7 building problem.

chrome/browser/ui/views/constrained_window_frame_simple.cc

Index: chrome/browser/ui/views/constrained_window_frame_simple.cc
diff --git a/chrome/browser/ui/views/constrained_window_frame_simple.cc b/chrome/browser/ui/views/constrained_window_frame_simple.cc
index 3292b063b0b6272fbd35844ffffe0ff647aa05d9..0a6cbb539c8daa5eb6fabe4c6d517da9d7a45c8c 100644
--- a/chrome/browser/ui/views/constrained_window_frame_simple.cc
+++ b/chrome/browser/ui/views/constrained_window_frame_simple.cc
@@ -190,7 +190,8 @@ int ConstrainedWindowFrameSimple::NonClientHitTest(const gfx::Point& point) {
 void ConstrainedWindowFrameSimple::GetWindowMask(const gfx::Size& size,
                                                  gfx::Path* window_mask) {
 #if defined(USE_AURA)
-  SkRect rect = {0, 0, size.width() - 1, size.height() - 1};
+  SkRect rect = {0, 0, static_cast<SkScalar>(size.width() - 1),
+                 static_cast<SkScalar>(size.height() - 1)};
 #else
   // There appears to be a bug in the window mask calculation on Windows
   // which causes the width, but not the height, to be off by one.