Added the detailed description for MSVC warning in BUILD.gn

skia/BUILD.gn

Index: skia/BUILD.gn
diff --git a/skia/BUILD.gn b/skia/BUILD.gn
index 8cf9fa4d5ab5c6763a99705b1f3f250015155087..b5c97d48a2c6cfc566b552420cf01e250a40d616 100644
--- a/skia/BUILD.gn
+++ b/skia/BUILD.gn
@@ -235,14 +235,16 @@ config("skia_library_config") {
 
     cflags = [
       # TODO(brettw) comment what these are.

[brettw, 2014/09/19 20:46:21]

Remove todo.

-      "/wd4244",
-      "/wd4267",
-      "/wd4341",
-      "/wd4345",
-      "/wd4390",
-      "/wd4554",
-      "/wd4748",
-      "/wd4800",
+      "/wd4244", # To suppress the warning conversion' conversion from 'type1( __int64)' to 'type2 (unsigned int)', possible loss of data

[brettw, 2014/09/19 20:46:22]

You can remove "to suppress the warning" on every line. If any of them are still
>80 cols, can you shorten them until they fit? The descriptions don't need to be
super detailed.

+      "/wd4267", # To suppress the warning  conversion from 'size_t' (64 bit) to 'type'(32 bit), possible loss of data
+      "/wd4341", # To suppress the warning  signed value is out of range for enum constant
+      "/wd4345", # To suppress the warning  If the new-initializer is omitted (with empty like '()'), then object is default-initialized.
+      "/wd4390", # To suppress the warning  ';' : empty controlled statement found in looping; is this what was intended?
+      "/wd4554", # To suppress the warning  'operator' : check operator precedence for possible error
+      "/wd4748", # To suppress the warning  The compiler will disable optimizations if a function has inline assembly
+                 # code containing flow of control (jmp or jcc, for example) statements.
+      "/wd4800", # To suppress the warning  forcing value to bool 'true' or 'false'
+                 # (assigning int variables to bool variables where the int variable contains only values true and false)
     ]
   }
 }