Add support for custom cursors set by windowless plugins. Windowless plugins typically set the cursor in NPP_HandleEvent for WM_MOUSEMOVE.The current implementation looks for the cursor type and if the typedoes not match predefinedcursor types defaults to the pointer cursor.

The fixes are as below:-
1. Marshal the HCURSOR after copying it to ensure that it  
   remains valid. This works as a HCURSOR is a user object  
   and can be used across processes. Ideally we would 
   like  to convert it to a skia bitmap but there are issues 
   with converting monochrome cursors.

2. Added support for marshaling platform specific data in  
   the webcursor Serialize/Deserialize functions. This is in  
   the form of functions like InitPlatformData,  
   SerializePlatformData, DeserializePlatformData, etc.  
   which are stubbed out for the other platforms.

3. Mimic webkit windowless plugin behavior where it sets a  
   flag to ignore the next setCursor after HandleEvent of  
   WM_MOUSEMOVE. If  we don't do this the cursor keeps  
   changing between a pointerCursor and the cursor set by  
   the plugin which also causes flicker.

4. Fixed the WebCursor::IsEqual function to ensure that it  
   checks all fields for equality.

5. The browser(RenderWidgetHostViewWin) now maintains a 
   WebCursor instance representing the current cursor. Any 
   cursor updates received from the renderer update the 
   current cursor member maintained by the browser.

6. We intercept the SetCursor API for windowless plugins 
   like Flash and Silverlight and remember the cursor being 
   set. We don't invoke the original API as the browser UI 
   thread would do it anyways. This fixes the annoying 
   cursor flicker caused by the windowless flash plugin 
   instance constantly setting the cursor even when the tab
   is not visible.

This fixes bug http://code.google.com/p/chromium/issues/detail?id=3800.

Review URL: http://codereview.chromium.org/15088

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@7798 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 53 insertions, 4 deletions

diff --git a/webkit/glue/webcursor.cc b/webkit/glue/webcursor.cc
index 4c943c3..76673e5 100644
--- a/webkit/glue/webcursor.cc
+++ b/webkit/glue/webcursor.cc
@@ -14,6 +14,7 @@
 
 WebCursor::WebCursor()
     : type_(WebCore::PlatformCursor::typePointer) {
+  InitPlatformData();
 }
 
 WebCursor::WebCursor(const WebCore::PlatformCursor& platform_cursor)
@@ -21,10 +22,31 @@ WebCursor::WebCursor(const WebCore::PlatformCursor& platform_cursor)
       hotspot_(platform_cursor.hotSpot().x(), platform_cursor.hotSpot().y()) {
   if (IsCustom())
     SetCustomData(platform_cursor.customImage().get());
+
+  InitPlatformData();
+}
+
+WebCursor::~WebCursor() {
+  Clear();
+}
+
+WebCursor::WebCursor(const WebCursor& other) {
+  InitPlatformData();
+  Copy(other);
+}
+
+const WebCursor& WebCursor::operator=(const WebCursor& other) {
+  if (this == &other)
+    return *this;
+
+  Clear();
+  Copy(other);
+  return *this;
 }
 
 bool WebCursor::Deserialize(const Pickle* pickle, void** iter) {
   int type, hotspot_x, hotspot_y, size_x, size_y, data_len;
+
   const char* data;
 
   // Leave |this| unmodified unless we are going to return success.
@@ -48,7 +70,7 @@ bool WebCursor::Deserialize(const Pickle* pickle, void** iter) {
     memcpy(&custom_data_[0], data, data_len);
   }
 
-  return true;
+  return DeserializePlatformData(pickle, iter);
 }
 
 bool WebCursor::Serialize(Pickle* pickle) const {
@@ -62,7 +84,10 @@ bool WebCursor::Serialize(Pickle* pickle) const {
   const char* data = NULL;
   if (!custom_data_.empty())
     data = &custom_data_[0];
-  return pickle->WriteData(data, custom_data_.size());
+  if (!pickle->WriteData(data, custom_data_.size()))
+    return false;
+
+  return SerializePlatformData(pickle);
 }
 
 bool WebCursor::IsCustom() const {
@@ -70,19 +95,43 @@ bool WebCursor::IsCustom() const {
 }
 
 bool WebCursor::IsEqual(const WebCursor& other) const {
-  if (!IsCustom())
-    return type_ == other.type_;
+  if (type_ != other.type_)
+    return false;
+
+  if (!IsPlatformDataEqual(other))
+    return false;
 
   return hotspot_ == other.hotspot_ &&
          custom_size_ == other.custom_size_ &&
          custom_data_ == other.custom_data_;
 }
 
+void WebCursor::Clear() {
+  type_ = WebCore::PlatformCursor::typePointer;
+  hotspot_.set_x(0);
+  hotspot_.set_y(0);
+  custom_size_.set_width(0);
+  custom_size_.set_height(0);
+  custom_data_.clear();
+  CleanupPlatformData();
+}
+
+void WebCursor::Copy(const WebCursor& other) {
+  type_ = other.type_;
+  hotspot_ = other.hotspot_;
+  custom_size_ = other.custom_size_;
+  custom_data_ = other.custom_data_;
+  CopyPlatformData(other);
+}
+
 #if !defined(OS_MACOSX)
 // The Mac version of Chromium is built with PLATFORM(CG) while all other
 // versions are PLATFORM(SKIA). We'll keep this Skia implementation here for
 // common use and put the Mac implementation in webcursor_mac.mm.
 void WebCursor::SetCustomData(WebCore::Image* image) {
+  if (!image)
+    return;
+
   WebCore::NativeImagePtr image_ptr = image->nativeImageForCurrentFrame();
   if (!image_ptr)
     return;