Handle the "debug_devtools" build arg in GN builds

R=brettw,pfeldman

Review URL: https://codereview.chromium.org/598353003

Cr-Commit-Position: refs/heads/master@{#297401}

chrome/browser/BUILD.gn

@@ -25,7 +25,10 @@ gypi_values = exec_script(
     [ "../chrome_browser.gypi" ])
 
 static_library("browser") {
-  configs += [ "//build/config/compiler:wexit_time_destructors" ]
+  configs += [
+    "//build/config/compiler:wexit_time_destructors",
+    "//third_party/WebKit/public:debug_devtools",
+  ]
   defines = []
   sources = []
   libs = []
@@ -273,10 +276,7 @@ static_library("browser") {
                            ".", "//chrome")
     #deps += [ "//components/nacl:nacl_browser" ]  TODO(GYP)
   }
-  # ["debug_devtools==1", {  TODO(GYP)
-  #   "defines": [
-  #     "DEBUG_DEVTOOLS=1",
-  # }],
+
   if (enable_configuration_policy) {
     sources += rebase_path(
         gypi_values.chrome_browser_policy_shared_with_ios_sources,

chrome/browser/devtools/BUILD.gn

@@ -40,17 +40,14 @@ static_library("devtools") {
   ]
   sources += get_target_outputs(":devtools_protocol_constants")
 
-  # TODO(GYP)
-  #     ['debug_devtools==1', {
-  #       'defines': [
-  #         'DEBUG_DEVTOOLS=1',
-  #        ],
-  #     }],
   if (is_win) {
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     cflags = [ "/wd4267" ]
   }
-  configs += [ "//build/config/compiler:wexit_time_destructors" ]
+  configs += [
+    "//build/config/compiler:wexit_time_destructors",
+    "//third_party/WebKit/public:debug_devtools",
+  ]
 
   deps = [
     ":devtools_protocol_constants",

chrome/browser/ui/BUILD.gn

@@ -19,7 +19,10 @@ static_library("ui") {
   defines = []
   libs = []
 
-  configs += [ "//build/config/compiler:wexit_time_destructors" ]
+  configs += [
+    "//build/config/compiler:wexit_time_destructors",
+    "//third_party/WebKit/public:debug_devtools",
+  ]
 
   # Since browser and browser_ui actually depend on each other,
   # we must omit the dependency from browser_ui to browser.
@@ -142,9 +145,6 @@ static_library("ui") {
       #"//native_client/src/trusted/service_runtime/service_runtime.gyp:sel",  TODO(GYP)
     ]
   }
-  if (debug_devtools) {
-    defines += [ "DEBUG_DEVTOOLS=1" ]
-  }
   if (enable_configuration_policy) {
     sources += rebase_path(gypi_values.chrome_browser_ui_policy_sources,
                            ".", "//chrome")