cc: disable denorm handling before calling into Skia's filter code.

cc/base/math_util.cc

Index: cc/base/math_util.cc
diff --git a/cc/base/math_util.cc b/cc/base/math_util.cc
index e3cb81f70cca5c92b9b881b744c97a34d3daada2..d28c195971f6cd14eb753b6d9eddd51d1dd082fb 100644
--- a/cc/base/math_util.cc
+++ b/cc/base/math_util.cc
@@ -7,6 +7,9 @@
 #include <algorithm>
 #include <cmath>
 #include <limits>
+#ifdef __SSE__
+#include <xmmintrin.h>
+#endif
 
 #include "base/trace_event/trace_event_argument.h"
 #include "base/values.h"
@@ -918,4 +921,18 @@ gfx::Vector3dF MathUtil::GetYAxis(const gfx::Transform& transform) {
                         transform.matrix().getFloat(2, 1));
 }
 
+ScopedSubnormalFloatDisabler::ScopedSubnormalFloatDisabler() {
+#ifdef __SSE__
+  // Turn on "subnormals are zero" and "flush to zero" CSR flags.
+  orig_state_ = _mm_getcsr();
+  _mm_setcsr(orig_state_ | 0x8040);
+#endif
+}
+
+ScopedSubnormalFloatDisabler::~ScopedSubnormalFloatDisabler() {
+#ifdef __SSE__
+  _mm_setcsr(orig_state_);
+#endif
+}
+
 }  // namespace cc