Add fixed raster scale use counter histograms.

third_party/WebKit/Source/core/frame/UseCounter.h

Index: third_party/WebKit/Source/core/frame/UseCounter.h
diff --git a/third_party/WebKit/Source/core/frame/UseCounter.h b/third_party/WebKit/Source/core/frame/UseCounter.h
index 041542f3c63f9b33dda4a28700b1f2ea83d86990..fc2e7aa031ccd03d25f536e855de5355ba05cb9a 100644
--- a/third_party/WebKit/Source/core/frame/UseCounter.h
+++ b/third_party/WebKit/Source/core/frame/UseCounter.h
@@ -1149,6 +1149,8 @@ public:
         Entry_Remove_Method_IsolatedFileSystem = 1331,
         Entry_GetParent_Method_IsolatedFileSystem = 1332,
         Entry_ToURL_Method_IsolatedFileSystem = 1333,
+        FixedRasterScale_BlurryContent = 1334,

[chrishtr, 2016/05/05 20:33:07]

Skip the underscores. The recent entries that have them are not following the
typical Blink style.

[vmpstr, 2016/05/06 19:53:48]

Done.

+        FixedRasterScale_PotentialPerformanceRegression = 1335,
 
         // Add new features immediately above this line. Don't change assigned
         // numbers of any item, and don't reuse removed slots.