[IME] Differentiate s_suppressNextKeypressEvent in WebViewImpl.

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index a0bd095a749a7bec78814557274cc5ca80085d98..2c2e07d5c39a09741a707223ab6b72ac00551af4 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -389,7 +389,7 @@ WebViewImpl::WebViewImpl(WebViewClient* client)
     , m_ignoreInputEvents(false)
     , m_compositorDeviceScaleFactorOverride(0)
     , m_rootLayerScale(1)
-    , m_suppressNextKeypressEvent(false)
+    , m_suppressNextKeypressEvent(Suppress_None)
     , m_imeAcceptEvents(true)
     , m_operationsAllowed(WebDragOperationNone)
     , m_dragOperation(WebDragOperationNone)
@@ -993,9 +993,9 @@ bool WebViewImpl::handleKeyEvent(const WebKeyboardEvent& event)
     // member.
     // The m_suppressNextKeypressEvent is set if the KeyDown is handled by
     // Webkit. A keyDown event is typically associated with a keyPress(char)
-    // event and a keyUp event. We reset this flag here as this is a new keyDown
+    // event and a keyUp event. We reset this state here as this is a new keyDown
     // event.
-    m_suppressNextKeypressEvent = false;
+    m_suppressNextKeypressEvent = Suppress_None;
 
     // If there is a select popup, it should be the one processing the event,
     // not the page.
@@ -1006,7 +1006,7 @@ bool WebViewImpl::handleKeyEvent(const WebKeyboardEvent& event)
         // We need to ignore the next Char event after this otherwise pressing
         // enter when selecting an item in the popup will go to the page.
         if (WebInputEvent::RawKeyDown == event.type)
-            m_suppressNextKeypressEvent = true;
+            m_suppressNextKeypressEvent = Suppress_KeyEventCancelled;
         return true;
     }
 
@@ -1030,7 +1030,7 @@ bool WebViewImpl::handleKeyEvent(const WebKeyboardEvent& event)
             // (Flash needs these keypress events to handle non-US keyboards.)
             Element* element = focusedElement();
             if (!element || !element->renderer() || !element->renderer()->isEmbeddedObject())
-                m_suppressNextKeypressEvent = true;
+                m_suppressNextKeypressEvent = Suppress_KeyEventCancelled; // FIXME: Adding this bug on purpose for testing.
         }
         return true;
     }
@@ -1063,8 +1063,8 @@ bool WebViewImpl::handleCharEvent(const WebKeyboardEvent& event)
     // handled by Webkit. A keyDown event is typically associated with a
     // keyPress(char) event and a keyUp event. We reset this flag here as it
     // only applies to the current keyPress event.
-    bool suppress = m_suppressNextKeypressEvent;
-    m_suppressNextKeypressEvent = false;
+    bool suppress = (m_suppressNextKeypressEvent != Suppress_None);
+    m_suppressNextKeypressEvent = Suppress_None;
 
     // If there is a select popup, it should be the one processing the event,
     // not the page.
@@ -2270,7 +2270,7 @@ bool WebViewImpl::setComposition(
 
     // If we're not going to fire a keypress event, then the keydown event was
     // canceled.  In that case, cancel any existing composition.
-    if (text.isEmpty() || m_suppressNextKeypressEvent) {
+    if (text.isEmpty() || m_suppressNextKeypressEvent == Suppress_KeyEventCancelled) {

[James Su, 2015/02/26 09:16:59]

1. Looks like Suppress_KeyEventHandled is not used at all. Is it correct?

2. I'm wondering how to distinguish between Handled (event.stopPropagation())
and Cancelled (event.preventDefault()) ?

3. According to my understanding, the major purpose of this logic is to make
sure a call to event.preventDefault() will actually prevent the default behavior
(the UA's behavior) of the event, which is, in this case, setting a composing
text.

Thus if we only look at the change of this line, it should be reasonable. But
I'm wondering what actually happens on the problematic websites?

As you said, the backspace got swallowed probably because the website wants to
prevent the default behavior of "navigating to previous page", then in this case
event.preventDefault() might be called by the website, instead of
event.stopPropagation().

If it's the case, then this change won't fix the problem.

         // A browser process sent an IPC message which does not contain a valid
         // string, which means an ongoing composition has been canceled.
         // If the ongoing composition has been canceled, replace the ongoing