Make GCC ninja log lines consistent with MSVC.

I recently switched over MSVC to simpler log lines from Ninja.  This makes GCC- or Clang-based builds use the same set of messages.  It's less noise when things go right; Ninja prints the whole line when a step fails.

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3540

Change-Id: I36b638ee180210c6fb35c2bccb1b6d3c58437d36
Reviewed-on: https://skia-review.googlesource.com/3540
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
diff --git a/gn/BUILD.gn b/gn/BUILD.gn
index dfab7e2..df45ada 100644
--- a/gn/BUILD.gn
+++ b/gn/BUILD.gn
@@ -435,7 +435,7 @@
     outputs = [
       "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",
     ]
-    description = "$cc_wrapper $cc ... -o {{output}}"
+    description = "compile {{source}}"
   }
 
   tool("cxx") {
@@ -445,7 +445,7 @@
     outputs = [
       "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",
     ]
-    description = "$cc_wrapper $cxx ... -o {{output}}"
+    description = "compile {{source}}"
   }
 
   tool("asm") {
@@ -455,7 +455,7 @@
     outputs = [
       "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",
     ]
-    description = "$cc_wrapper $cc ... -o {{output}}"
+    description = "compile {{source}}"
   }
 
   tool("alink") {
@@ -465,7 +465,7 @@
     ]
     default_output_extension = ".a"
     output_prefix = "lib"
-    description = "$ar {{output}} ..."
+    description = "link {{output}}"
   }
 
   tool("solink") {
@@ -482,7 +482,7 @@
     ]
     output_prefix = "lib"
     default_output_extension = ".so"
-    description = "$cc_wrapper $cxx -shared ... -o {{output}}"
+    description = "link {{output}}"
   }
 
   tool("link") {
@@ -490,14 +490,16 @@
     outputs = [
       "{{root_out_dir}}/{{target_output_name}}{{output_extension}}",
     ]
-    description = "$cc_wrapper $cxx ... -o {{output}}"
+    description = "link {{output}}"
   }
 
   tool("stamp") {
     command = "touch {{output}}"
+    description = "stamp {{output}}"
   }
 
   tool("copy") {
     command = "ln -f {{source}} {{output}} 2>/dev/null || (rm -rf {{output}} && cp -af {{source}} {{output}})"
+    description = "copy {{source}} {{output}}"
   }
 }