diff --git a/deps/v8/build/common.gypi b/deps/v8/build/common.gypi
index 2d8dc11b70d..7f084b8c1db 100644
--- a/deps/v8/build/common.gypi
+++ b/deps/v8/build/common.gypi
@@ -239,6 +239,7 @@
           'WIN32',
         ],
         'msvs_configuration_attributes': {
+          'OutputDirectory': '<(DEPTH)\\build\\$(ConfigurationName)',
           'IntermediateDirectory': '$(OutDir)\\obj\\$(ProjectName)',
           'CharacterSet': '1',
         },
@@ -270,7 +271,7 @@
         'target_conditions': [
           ['_toolset=="host"', {
             'variables': {
-              'm32flag': '<!((echo | $(echo ${CXX_host:-$(which g++)}) -m32 -E - > /dev/null 2>&1) && echo "-m32" || true)',
+              'm32flag': '<!((echo | $(echo ${CXX_host:-$(which g++)}) -m32 -E - > /dev/null 2>&1) && echo -n "-m32" || true)',
             },
             'cflags': [ '<(m32flag)' ],
             'ldflags': [ '<(m32flag)' ],
@@ -280,7 +281,7 @@
           }],
           ['_toolset=="target"', {
             'variables': {
-              'm32flag': '<!((echo | $(echo ${CXX_target:-${CXX:-$(which g++)}}) -m32 -E - > /dev/null 2>&1) && echo "-m32" || true)',
+              'm32flag': '<!((echo | $(echo ${CXX_target:-${CXX:-$(which g++)}}) -m32 -E - > /dev/null 2>&1) && echo -n "-m32" || true)',
             },
             'cflags': [ '<(m32flag)' ],
             'ldflags': [ '<(m32flag)' ],
@@ -323,7 +324,7 @@
         },
         'conditions': [
           ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd"', {
-            'cflags': [ '-Wno-unused-parameter',
+            'cflags': [ '-Wall', '<(werror)', '-W', '-Wno-unused-parameter',
                         '-Wnon-virtual-dtor', '-Woverloaded-virtual' ],
           }],
         ],
diff --git a/deps/v8/src/ia32/lithium-codegen-ia32.cc b/deps/v8/src/ia32/lithium-codegen-ia32.cc
index 7c9c8826065..2c6a916b04c 100644
--- a/deps/v8/src/ia32/lithium-codegen-ia32.cc
+++ b/deps/v8/src/ia32/lithium-codegen-ia32.cc
@@ -2359,10 +2359,15 @@ void LCodeGen::EmitPushTaggedOperand(LOperand* operand) {
 
 // Check for cases where EmitLoadFieldOrConstantFunction needs to walk the
 // prototype chain, which causes unbounded code generation.
-static bool CompactEmit(
-    SmallMapList* list, Handle<String> name, int i, Isolate* isolate) {
-  LookupResult lookup(isolate);
+static bool CompactEmit(SmallMapList* list,
+                        Handle<String> name,
+                        int i,
+                        Isolate* isolate) {
   Handle<Map> map = list->at(i);
+  // If the map has ElementsKind transitions, we will generate map checks
+  // for each kind in __ CompareMap(..., ALLOW_ELEMENTS_TRANSITION_MAPS).
+  if (map->elements_transition_map() != NULL) return false;
+  LookupResult lookup(isolate);
   map->LookupInDescriptors(NULL, *name, &lookup);
   return lookup.IsFound() &&
       (lookup.type() == FIELD || lookup.type() == CONSTANT_FUNCTION);
diff --git a/deps/v8/src/version.cc b/deps/v8/src/version.cc
index 03526d37642..9b9c9beb259 100644
--- a/deps/v8/src/version.cc
+++ b/deps/v8/src/version.cc
@@ -35,7 +35,7 @@
 #define MAJOR_VERSION     3
 #define MINOR_VERSION     11
 #define BUILD_NUMBER      10
-#define PATCH_LEVEL       10
+#define PATCH_LEVEL       12
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)
 #define IS_CANDIDATE_VERSION 0
diff --git a/deps/v8/src/x64/lithium-codegen-x64.cc b/deps/v8/src/x64/lithium-codegen-x64.cc
index f62528e34a4..7dc38a1429f 100644
--- a/deps/v8/src/x64/lithium-codegen-x64.cc
+++ b/deps/v8/src/x64/lithium-codegen-x64.cc
@@ -2235,10 +2235,15 @@ void LCodeGen::EmitLoadFieldOrConstantFunction(Register result,
 
 // Check for cases where EmitLoadFieldOrConstantFunction needs to walk the
 // prototype chain, which causes unbounded code generation.
-static bool CompactEmit(
-    SmallMapList* list, Handle<String> name, int i, Isolate* isolate) {
-  LookupResult lookup(isolate);
+static bool CompactEmit(SmallMapList* list,
+                        Handle<String> name,
+                        int i,
+                        Isolate* isolate) {
   Handle<Map> map = list->at(i);
+  // If the map has ElementsKind transitions, we will generate map checks
+  // for each kind in __ CompareMap(..., ALLOW_ELEMENTS_TRANSITION_MAPS).
+  if (map->elements_transition_map() != NULL) return false;
+  LookupResult lookup(isolate);
   map->LookupInDescriptors(NULL, *name, &lookup);
   return lookup.IsFound() &&
       (lookup.type() == FIELD || lookup.type() == CONSTANT_FUNCTION);
diff --git a/deps/v8/test/mjsunit/regress/regress-crbug-134055.js b/deps/v8/test/mjsunit/regress/regress-crbug-134055.js
new file mode 100644
index 00000000000..9b658fb6f65
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/regress-crbug-134055.js
@@ -0,0 +1,63 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+function crash(obj) {
+  return obj.foo;
+}
+
+function base(number_of_properties) {
+  var result = new Array();
+  for (var i = 0; i < number_of_properties; i++) {
+    result["property" + i] = "value" + i;
+  }
+  result.foo = number_of_properties;
+  return result;
+}
+
+var a = base(12);
+var b = base(13);
+var c = base(14);
+var d = base(15);
+
+crash(a);  // Premonomorphic.
+crash(a);
+crash(b);
+crash(c);
+crash(d);  // Polymorphic, degree 4.
+
+//Prepare ElementsKind transition map chain.
+var x = base(13);
+x[0] = "object";
+x = base(14);
+x[0] = "object";
+x = base(15);
+x[0] = "object";
+
+%OptimizeFunctionOnNextCall(crash);
+crash(a);