Switch third_party/gflags to use updated GitHub repo.

third_party/gflags/BUILD.gn

Index: third_party/gflags/BUILD.gn
diff --git a/third_party/gflags/BUILD.gn b/third_party/gflags/BUILD.gn
index e8a5a13ff657d79c2e3e89b2cff75404bf79fec4..af41b7ecbfceb25ca69f78db1f2ecfa15bf14faf 100644
--- a/third_party/gflags/BUILD.gn
+++ b/third_party/gflags/BUILD.gn
@@ -15,7 +15,7 @@ if (is_win) {
 config("gflags_config") {
   include_dirs = [
     "$gflags_gen_arch_root/include",  # For configured files.
-    "src",  # For everything else.
+    "src/src",  # For everything else.
   ]
 
   defines = [
@@ -35,30 +35,39 @@ config("gflags_config") {
 }
 
 source_set("gflags") {
+  cflags = []
   sources = [
-    "src/gflags.cc",
-    "src/gflags_completions.cc",
-    "src/gflags_reporting.cc",
+    "src/src/gflags.cc",
+    "src/src/gflags_completions.cc",
+    "src/src/gflags_reporting.cc",
   ]
   if (is_win) {
-    sources += [ "src/windows/port.cc" ]
+    sources += [ "src/src/windows_port.cc" ]
 
-    cflags = [
+    cflags += [
       "/wd4005",  # WIN32_LEAN_AND_MEAN.
       "/wd4267",  # Conversion from size_t to "type".
     ]
   }
 
-  include_dirs = [ "$gflags_gen_arch_root/include/private" ]  # For config.h
+  include_dirs = [
+    "$gflags_gen_arch_root/include/gflags",  # For configured files.
+    "$gflags_gen_arch_root/include/private",  # For config.h
+  ]
 
   public_configs = [ ":gflags_config" ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
 
+  if (is_win) {
+    configs -= [ "//build/config/win:unicode" ]
+  }
+
   if (is_clang) {
     # TODO(andrew): Look into fixing this warning upstream:
     # http://code.google.com/p/webrtc/issues/detail?id=760
     configs -= [ "//build/config/clang:extra_warnings" ]
+    cflags += [ "-Wno-microsoft-include" ]
   }
 }