Track the active ExtensionKeybindingRegistry and make it available to EventRewriter.

chrome/browser/chromeos/events/event_rewriter.cc

Index: chrome/browser/chromeos/events/event_rewriter.cc
diff --git a/chrome/browser/chromeos/events/event_rewriter.cc b/chrome/browser/chromeos/events/event_rewriter.cc
index 314a3ecd272cc4987b081631fbc14a31bac25219..f194f0fd5ae6f96e97765e06af8d059a3cf24f1c 100644
--- a/chrome/browser/chromeos/events/event_rewriter.cc
+++ b/chrome/browser/chromeos/events/event_rewriter.cc
@@ -16,6 +16,7 @@
 #include "base/strings/string_util.h"
 #include "base/sys_info.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host_impl.h"
+#include "chrome/browser/extensions/extension_commands_global_registry.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/common/pref_names.h"
 #include "chromeos/chromeos_switches.h"
@@ -104,6 +105,36 @@ bool IsISOLevel5ShiftUsedByCurrentInputMethod() {
   return manager->IsISOLevel5ShiftUsedByCurrentInputMethod();
 }
 
+bool IsExtensionCommandRegistered(const ui::KeyEvent& key_event) {
+  // Some keyboard events for ChromeOS get rewritten, such as:
+  // Search+Shift+Left gets converted to Shift+Home (BeginDocument).
+  // This doesn't make sense if the user has assigned that shortcut
+  // to an extension. Because:
+  // 1) The extension would, upon seeing a request for Ctrl+Shift+Home have
+  //    to register for Shift+Home, instead.
+  // 2) The conversion is unnecessary, because Shift+Home (BeginDocument) isn't
+  //    going to be executed.
+  // Therefore, we skip converting the accelerator if an extension has
+  // registered for this shortcut.
+  Profile* profile = ProfileManager::GetActiveUserProfile();
+  if (!profile)
+    return false;
+
+  int modifiers = ui::EF_NONE;
+  if (key_event.IsShiftDown())

[sky, 2014/09/16 02:34:48]

Isn't this the same as looking at flags(), eg
flags = key_event.flags() & (modifiers you care about)?

[sky, 2014/09/16 16:44:35]

It doesn't seem like you addressed this comment.

[David Tseng, 2014/09/16 20:42:57]

That would indeed simplify this logic. Done.

+    modifiers |= ui::EF_SHIFT_DOWN;
+  if (key_event.IsControlDown())
+    modifiers |= ui::EF_CONTROL_DOWN;
+  if (key_event.IsAltDown())
+    modifiers |= ui::EF_ALT_DOWN;
+  if (key_event.IsCommandDown())
+    modifiers |= ui::EF_COMMAND_DOWN;
+  ui::Accelerator accelerator(key_event.key_code(), modifiers);
+
+  return extensions::ExtensionCommandsGlobalRegistry::Get(profile)

[sky, 2014/09/16 02:34:48]

Is the global registry always non-NULL?

[David Tseng, 2014/09/16 04:11:52]

Turned out the ProfileManager above can be NULL in a unit test, so Profile* can
be NULL and likely ExtensionCommandsGlobalRegistry. Checking them all now.

+      ->IsRegisteredForActiveWindow(accelerator);
+}
+
 EventRewriter::DeviceType GetDeviceType(const std::string& device_name) {
   std::vector<std::string> tokens;
   Tokenize(device_name, " .", &tokens);
@@ -360,6 +391,8 @@ bool EventRewriter::RewriteWithKeyboardRemappingsByKeyCode(
 ui::EventRewriteStatus EventRewriter::RewriteKeyEvent(
     const ui::KeyEvent& key_event,
     scoped_ptr<ui::Event>* rewritten_event) {
+  if (IsExtensionCommandRegistered(key_event))
+    return ui::EVENT_REWRITE_CONTINUE;
   if (key_event.source_device_id() != ui::ED_UNKNOWN_DEVICE)
     DeviceKeyPressedOrReleased(key_event.source_device_id());
   MutableKeyState state = {key_event.flags(), key_event.key_code()};