diff --git a/browser/default_app/main.js b/browser/default_app/main.js
index 3bfb5b510..2aff83e30 100644
--- a/browser/default_app/main.js
+++ b/browser/default_app/main.js
@@ -1,6 +1,7 @@
 var app = require('app');
 var dialog = require('dialog');
 var path = require('path');
+var optimist = require('optimist');
 
 // Quit when all windows are closed and no other one is listening to this.
 app.on('window-all-closed', function() {
@@ -8,8 +9,7 @@ app.on('window-all-closed', function() {
     app.quit();
 });
 
-process.argv.splice(1, 0, 'dummyScript');
-var argv = require('optimist').argv;
+var argv = optimist(process.argv.slice(1)).argv;
 
 // Start the specified app if there is one specified in command line, otherwise
 // start the default app.
diff --git a/browser/ui/accelerator_util.cc b/browser/ui/accelerator_util.cc
index fe1b7a962..c1563ca12 100644
--- a/browser/ui/accelerator_util.cc
+++ b/browser/ui/accelerator_util.cc
@@ -4,6 +4,8 @@
 
 #include "browser/ui/accelerator_util.h"
 
+#include <stdio.h>
+
 #include <string>
 
 #include "base/string_util.h"
@@ -15,27 +17,79 @@ namespace accelerator_util {
 
 namespace {
 
-// Convert "Command" to "Ctrl" on non-Mac
-std::string NormalizeShortcutSuggestion(const std::string& suggestion) {
-#if defined(OS_MACOSX)
-  return suggestion;
-#endif
+// Return key code of the char.
+ui::KeyboardCode KeyboardCodeFromCharCode(char c, bool* shifted) {
+  *shifted = false;
+  switch (c) {
+    case 8: case 0x7F: return ui::VKEY_BACK;
+    case 9: return ui::VKEY_TAB;
+    case 0xD: case 3: return ui::VKEY_RETURN;
+    case 0x1B: return ui::VKEY_ESCAPE;
+    case ' ': return ui::VKEY_SPACE;
 
-  std::string key;
-  std::vector<std::string> tokens;
-  base::SplitString(suggestion, '+', &tokens);
-  for (size_t i = 0; i < tokens.size(); i++) {
-    if (tokens[i] == "Command")
-      tokens[i] = "Ctrl";
+    case 'a': return ui::VKEY_A;
+    case 'b': return ui::VKEY_B;
+    case 'c': return ui::VKEY_C;
+    case 'd': return ui::VKEY_D;
+    case 'e': return ui::VKEY_E;
+    case 'f': return ui::VKEY_F;
+    case 'g': return ui::VKEY_G;
+    case 'h': return ui::VKEY_H;
+    case 'i': return ui::VKEY_I;
+    case 'j': return ui::VKEY_J;
+    case 'k': return ui::VKEY_K;
+    case 'l': return ui::VKEY_L;
+    case 'm': return ui::VKEY_M;
+    case 'n': return ui::VKEY_N;
+    case 'o': return ui::VKEY_O;
+    case 'p': return ui::VKEY_P;
+    case 'q': return ui::VKEY_Q;
+    case 'r': return ui::VKEY_R;
+    case 's': return ui::VKEY_S;
+    case 't': return ui::VKEY_T;
+    case 'u': return ui::VKEY_U;
+    case 'v': return ui::VKEY_V;
+    case 'w': return ui::VKEY_W;
+    case 'x': return ui::VKEY_X;
+    case 'y': return ui::VKEY_Y;
+    case 'z': return ui::VKEY_Z;
+
+    case ')': *shifted = true; case '0': return ui::VKEY_0;
+    case '!': *shifted = true; case '1': return ui::VKEY_1;
+    case '@': *shifted = true; case '2': return ui::VKEY_2;
+    case '#': *shifted = true; case '3': return ui::VKEY_3;
+    case '$': *shifted = true; case '4': return ui::VKEY_4;
+    case '%': *shifted = true; case '5': return ui::VKEY_5;
+    case '^': *shifted = true; case '6': return ui::VKEY_6;
+    case '&': *shifted = true; case '7': return ui::VKEY_7;
+    case '*': *shifted = true; case '8': return ui::VKEY_8;
+    case '(': *shifted = true; case '9': return ui::VKEY_9;
+
+    case ':': *shifted = true; case ';': return ui::VKEY_OEM_1;
+    case '+': *shifted = true; case '=': return ui::VKEY_OEM_PLUS;
+    case '<': *shifted = true; case ',': return ui::VKEY_OEM_COMMA;
+    case '_': *shifted = true; case '-': return ui::VKEY_OEM_MINUS;
+    case '>': *shifted = true; case '.': return ui::VKEY_OEM_PERIOD;
+    case '?': *shifted = true; case '/': return ui::VKEY_OEM_2;
+    case '~': *shifted = true; case '`': return ui::VKEY_OEM_3;
+    case '{': *shifted = true; case '[': return ui::VKEY_OEM_4;
+    case '|': *shifted = true; case '\\': return ui::VKEY_OEM_5;
+    case '}': *shifted = true; case ']': return ui::VKEY_OEM_6;
+    case '"': *shifted = true; case '\'': return ui::VKEY_OEM_7;
+
+    default: return ui::VKEY_UNKNOWN;
   }
-  return JoinString(tokens, '+');
 }
 
 }  // namespace
 
 bool StringToAccelerator(const std::string& description,
                          ui::Accelerator* accelerator) {
-  std::string shortcut(NormalizeShortcutSuggestion(description));
+  if (!IsStringASCII(description)) {
+    LOG(ERROR) << "The accelerator string can only contain ASCII characters";
+    return false;
+  }
+  std::string shortcut(StringToLowerASCII(description));
 
   std::vector<std::string> tokens;
   base::SplitString(shortcut, '+', &tokens);
@@ -48,65 +102,77 @@ bool StringToAccelerator(const std::string& description,
   int modifiers = ui::EF_NONE;
   ui::KeyboardCode key = ui::VKEY_UNKNOWN;
   for (size_t i = 0; i < tokens.size(); i++) {
-    if (tokens[i] == "Ctrl") {
+    // We use straight comparing instead of map because the accelerator tends
+    // to be correct and usually only uses few special tokens.
+    if (tokens[i].size() == 1) {
+      bool shifted = false;
+      key = KeyboardCodeFromCharCode(tokens[i][0], &shifted);
+      if (shifted)
+        modifiers |= ui::EF_SHIFT_DOWN;
+    } else if (tokens[i] == "ctrl") {
       modifiers |= ui::EF_CONTROL_DOWN;
-    } else if (tokens[i] == "Command") {
+    } else if (tokens[i] == "command") {
+      // The "Command" would be translated to "Ctrl" on platforms other than
+      // OS X.
+#if defined(OS_MACOSX)
       modifiers |= ui::EF_COMMAND_DOWN;
-    } else if (tokens[i] == "Alt") {
+#else
+      modifiers |= ui::EF_CONTROL_DOWN;
+#endif
+    } else if (tokens[i] == "alt") {
       modifiers |= ui::EF_ALT_DOWN;
-    } else if (tokens[i] == "Shift") {
+    } else if (tokens[i] == "shift") {
       modifiers |= ui::EF_SHIFT_DOWN;
-    } else if (tokens[i].size() == 1) {
-      char token = tokens[i][0];
-
-      if (key != ui::VKEY_UNKNOWN) {
-        // Multiple key assignments.
-        key = ui::VKEY_UNKNOWN;
-        return false;
-      }
-      if (token >= 'A' && token <= 'Z') {
-        key = static_cast<ui::KeyboardCode>(ui::VKEY_A + (token - 'A'));
-      } else if (token >= '0' && token <= '9') {
-        key = static_cast<ui::KeyboardCode>(ui::VKEY_0 + (token - '0'));
-      } else if (token >= '*' && token <= '/') {
-        // *+,-./
-        key = static_cast<ui::KeyboardCode>(
-            ui::VKEY_MULTIPLY + (token - '*'));
+    } else if (tokens[i] == "tab") {
+      key = ui::VKEY_TAB;
+    } else if (tokens[i] == "space") {
+      key = ui::VKEY_SPACE;
+    } else if (tokens[i] == "backspace") {
+      key = ui::VKEY_BACK;
+    } else if (tokens[i] == "delete") {
+      key = ui::VKEY_DELETE;
+    } else if (tokens[i] == "enter" || tokens[i] == "return") {
+      key = ui::VKEY_RETURN;
+    } else if (tokens[i] == "up") {
+      key = ui::VKEY_UP;
+    } else if (tokens[i] == "down") {
+      key = ui::VKEY_DOWN;
+    } else if (tokens[i] == "left") {
+      key = ui::VKEY_LEFT;
+    } else if (tokens[i] == "right") {
+      key = ui::VKEY_RIGHT;
+    } else if (tokens[i] == "home") {
+      key = ui::VKEY_HOME;
+    } else if (tokens[i] == "end") {
+      key = ui::VKEY_END;
+    } else if (tokens[i] == "pagedown") {
+      key = ui::VKEY_PRIOR;
+    } else if (tokens[i] == "pageup") {
+      key = ui::VKEY_NEXT;
+    } else if (tokens[i] == "esc") {
+      key = ui::VKEY_ESCAPE;
+    } else if (tokens[i] == "volumemute") {
+      key = ui::VKEY_VOLUME_MUTE;
+    } else if (tokens[i] == "volumeup") {
+      key = ui::VKEY_VOLUME_UP;
+    } else if (tokens[i] == "volumedown") {
+      key = ui::VKEY_VOLUME_DOWN;
+    } else if (tokens[i] == "medianexttrack") {
+      key = ui::VKEY_MEDIA_NEXT_TRACK;
+    } else if (tokens[i] == "mediaprevioustrack") {
+      key = ui::VKEY_MEDIA_PREV_TRACK;
+    } else if (tokens[i] == "mediastop") {
+      key = ui::VKEY_MEDIA_STOP;
+    } else if (tokens[i] == "mediaplaypause") {
+      key = ui::VKEY_MEDIA_PLAY_PAUSE;
+    } else if (tokens[i].size() > 1 && tokens[i][0] == 'f') {
+      // F1 - F24.
+      int n;
+      if (base::StringToInt(tokens[i].c_str() + 1, &n)) {
+        key = static_cast<ui::KeyboardCode>(ui::VKEY_F1 + n - 1);
       } else {
-        switch (token) {
-          case ':':
-          case ';':
-            key = ui::VKEY_OEM_1;
-            break;
-          case '?':
-          case '/':
-            key = ui::VKEY_OEM_2;
-            break;
-          case '~':
-          case '`':
-            key = ui::VKEY_OEM_3;
-            break;
-          case '{':
-          case '[':
-            key = ui::VKEY_OEM_4;
-            break;
-          case '|':
-          case '\\':
-            key = ui::VKEY_OEM_5;
-            break;
-          case '}':
-          case ']':
-            key = ui::VKEY_OEM_6;
-            break;
-          case '\"':
-          case '\'':
-            key = ui::VKEY_OEM_7;
-            break;
-          default:
-            LOG(WARNING) << "Invalid accelerator character: " << tokens[i];
-            key = ui::VKEY_UNKNOWN;
-            return false;
-        }
+        LOG(WARNING) << tokens[i] << "is not available on keyboard";
+        return false;
       }
     } else {
       LOG(WARNING) << "Invalid accelerator token: " << tokens[i];
@@ -114,6 +180,11 @@ bool StringToAccelerator(const std::string& description,
     }
   }
 
+  if (key == ui::VKEY_UNKNOWN) {
+    LOG(WARNING) << "The accelerator doesn't contain a valid key";
+    return false;
+  }
+
   *accelerator = ui::Accelerator(key, modifiers);
   SetPlatformAccelerator(accelerator);
   return true;