Roll clang 289944:295762.

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 8f5712039c167f581c359ebcc3ded33bf3fc076c..9137028913079075f8c41a1e43753d231662ff34 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -1084,7 +1084,10 @@ config("default_warnings") {
         "-Wno-shift-negative-value",
       ]
     }
-    if (!is_nacl && !use_xcode_clang) {
+
+    # use_xcode_clang only refers to the iOS toolchain, host binaries use
+    # chromium's clang always.
+    if (!is_nacl && (!use_xcode_clang || current_toolchain == host_toolchain)) {
       # Flags NaCl (Clang 3.7) and Xcode 7.3 (Clang clang-703.0.31) do not
       # recognize.
       cflags += [
@@ -1099,16 +1102,13 @@ config("default_warnings") {
 
         # TODO(thakis): Consider turning this on, https://crbug.com/691120
         "-Wno-block-capture-autoreleasing",
-      ]
-      if (llvm_force_head_revision) {
-        cflags += [
-          # TODO(hans): https://crbug.com/681136
-          "-Wno-unused-lambda-capture",
 
-          # TODO(thakis ): https://crbug.com/683349
-          "-Wno-user-defined-warnings",
-        ]
-      }
+        # TODO(hans): https://crbug.com/681136
+        "-Wno-unused-lambda-capture",
+
+        # TODO(thakis ): https://crbug.com/683349
+        "-Wno-user-defined-warnings",
+      ]
     }
   }
 }