Support dragging texts into Android WebView.

content/browser/android/content_view_core_impl.cc

Index: content/browser/android/content_view_core_impl.cc
diff --git a/content/browser/android/content_view_core_impl.cc b/content/browser/android/content_view_core_impl.cc
index d70219a71ef275a274ba0f2cb91ad79fe20f34a8..82d99b8e22764d407017abaaeac35e0b255f9ac7 100644
--- a/content/browser/android/content_view_core_impl.cc
+++ b/content/browser/android/content_view_core_impl.cc
@@ -54,6 +54,8 @@
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "ui/android/view_android.h"
 #include "ui/android/window_android.h"
+#include "ui/base/dragdrop/drop_target_event.h"
+#include "ui/base/dragdrop/os_exchange_data_provider_android.h"
 #include "ui/events/android/motion_event_android.h"
 #include "ui/gfx/android/java_bitmap.h"
 #include "ui/gfx/geometry/point_conversions.h"
@@ -88,6 +90,15 @@ enum PopupItemType {
   POPUP_ITEM_TYPE_ENABLED,
 };
 
+enum DragEventActions {
+  ACTION_DRAG_STARTED = 1,
+  ACTION_DRAG_LOCATION,
+  ACTION_DROP,
+  ACTION_DRAG_ENDED,
+  ACTION_DRAG_ENTERED,
+  ACTION_DRAG_EXITED,
+};
+
 const void* const kContentViewUserDataKey = &kContentViewUserDataKey;
 
 int GetRenderProcessIdFromRenderViewHost(RenderViewHost* host) {
@@ -1409,6 +1420,64 @@ void ContentViewCoreImpl::SetBackgroundOpaque(JNIEnv* env,
   }
 }
 
+void ContentViewCoreImpl::OnDragEvent(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jobject>& jobj,
+    int action,
+    const JavaParamRef<jintArray>& j_locations,
+    const base::android::JavaParamRef<jstring>& content) {
+  WebContentsViewAndroid* wcva = static_cast<WebContentsViewAndroid*>(
+      static_cast<WebContentsImpl*>(web_contents())->GetView());
+
+  std::vector<int> locations;
+  base::android::JavaIntArrayToIntVector(env, j_locations, &locations);
+  int x = locations[0];
+  int y = locations[1];
+  int screen_x = locations[2];
+  int screen_y = locations[3];
+
+  switch (action) {
+    case ACTION_DRAG_ENTERED: {
+      ui::OSExchangeData data(new ui::OSExchangeDataProviderAndroid());
+      // Text being dragged is not available when drag enters. Use an empty
+      // string to declare that the DropData contains string. The DropData will
+      // be updated with real string being dragged during ACTION_DROP.
+      data.SetString(base::string16());
+      ui::DropTargetEvent event(data, gfx::Point(x, y),
+                                gfx::Point(screen_x, screen_y),
+                                ui::DragDropTypes::DRAG_COPY);
+
+      wcva->OnDragEntered(event);
+      break;
+    }
+    case ACTION_DRAG_LOCATION: {
+      ui::OSExchangeData data(new ui::OSExchangeDataProviderAndroid());
+      ui::DropTargetEvent event(data, gfx::Point(x, y),
+                                gfx::Point(screen_x, screen_y),
+                                ui::DragDropTypes::DRAG_COPY);
+
+      wcva->OnDragUpdated(event);
+      break;
+    }
+    case ACTION_DROP: {
+      base::string16 text_to_drop = ConvertJavaStringToUTF16(env, content);
+      ui::OSExchangeData data(new ui::OSExchangeDataProviderAndroid());
+      data.SetString(text_to_drop);
+      ui::DropTargetEvent event(data, gfx::Point(x, y),
+                                gfx::Point(screen_x, screen_y),
+                                ui::DragDropTypes::DRAG_COPY);
+
+      wcva->OnPerformDrop(event);
+      break;
+    }
+    case ACTION_DRAG_EXITED:
+      wcva->OnDragExited();
+      break;
+    case ACTION_DRAG_ENDED:
+      break;
+  }
+}
+
 void ContentViewCoreImpl::RequestTextSurroundingSelection(
     int max_length,
     const base::Callback<