SPM: Fix VK issue of special chars with no key code

- Make InputMethodMus not forwarding synthetic key events
  as InputMethodChromeOS does not expect to receive them;
- ChromeVirtualKeyboardDelegate to insert char to the
  correct ui::TextInputClient instance;

Bug: 931931
Change-Id: If783fcf53c833c360d6a733d22b5b30308528363
Reviewed-on: https://chromium-review.googlesource.com/c/1474635Reviewed-by: Darren Shen <shend@chromium.org>
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#632396}

chrome/browser/extensions/api/virtual_keyboard_private/chrome_virtual_keyboard_delegate.cc

@@ -71,6 +71,16 @@ keyboard::mojom::ContainerType ConvertKeyboardModeToContainerType(int mode) {
   return keyboard::mojom::ContainerType::kFullWidth;
 }
 
+// Returns the ui::TextInputClient of the active InputMethod or nullptr.
+ui::TextInputClient* GetFocusedTextInputClient() {
+  ui::InputMethod* input_method =
+      ui::IMEBridge::Get()->GetInputContextHandler()->GetInputMethod();
+  if (!input_method)
+    return nullptr;
+
+  return input_method->GetTextInputClient();
+}
+
 const char kKeyDown[] = "keydown";
 const char kKeyUp[] = "keyup";
 
@@ -104,16 +114,12 @@ bool SendKeyEventImpl(const std::string& type,
 
   ui::KeyboardCode code = static_cast<ui::KeyboardCode>(key_code);
 
-  ui::InputMethod* input_method = host->GetInputMethod();
   if (code == ui::VKEY_UNKNOWN) {
     // Handling of special printable characters (e.g. accented characters) for
     // which there is no key code.
     if (event_type == ui::ET_KEY_RELEASED) {
-      if (!input_method)
-        return false;
-
       // This can be null if no text input field is focused.
-      ui::TextInputClient* tic = input_method->GetTextInputClient();
+      ui::TextInputClient* tic = GetFocusedTextInputClient();
 
       SendProcessKeyEvent(ui::ET_KEY_PRESSED, host);
 
@@ -196,12 +202,7 @@ bool ChromeVirtualKeyboardDelegate::HideKeyboard() {
 
 bool ChromeVirtualKeyboardDelegate::InsertText(const base::string16& text) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-  ui::InputMethod* input_method =
-      ui::IMEBridge::Get()->GetInputContextHandler()->GetInputMethod();
-  if (!input_method)
-    return false;
-
-  ui::TextInputClient* tic = input_method->GetTextInputClient();
+  ui::TextInputClient* tic = GetFocusedTextInputClient();
   if (!tic || tic->GetTextInputType() == ui::TEXT_INPUT_TYPE_NONE)
     return false;
 

ui/aura/mus/input_method_mus.cc

@@ -107,8 +107,9 @@ ui::EventDispatchDetails InputMethodMus::DispatchKeyEvent(
   DCHECK(event->type() == ui::ET_KEY_PRESSED ||
          event->type() == ui::ET_KEY_RELEASED);
 
-  // If no text input client, do nothing.
-  if (!GetTextInputClient()) {
+  // If no text input client or the event is synthesized, dispatch the devent
+  // directly without forwarding it to the real input method.
+  if (!GetTextInputClient() || (event->flags() & ui::EF_IS_SYNTHESIZED)) {
     return DispatchKeyEventPostIME(
         event,
         base::BindOnce(&CallEventResultCallback, std::move(ack_callback)));