rebuild the nav cache on mouse clicks during page load

On the first tap down, send a message to rebuild the nav
cache so that double taps have a better chance of having
some alignment information to work with.

Also, pass scale information to getBlockLeftEdge to
restrict the alignment search

core/java/android/webkit/WebView.java

@@ -3814,6 +3814,8 @@ public class WebView extends AbsoluteLayout
                 } else {
                     mTouchMode = TOUCH_INIT_MODE;
                     mPreventDrag = mForwardTouchEvents;
+                    mWebViewCore.sendMessage(
+                            EventHub.UPDATE_FRAME_CACHE_IF_LOADING);
                     if (mLogEvent && eventTime - mLastTouchUpTime < 1000) {
                         EventLog.writeEvent(EVENT_LOG_DOUBLE_TAP_DURATION,
                                 (eventTime - mLastTouchUpTime), eventTime);
@@ -4681,7 +4683,7 @@ public class WebView extends AbsoluteLayout
             // mLastTouchX and mLastTouchY are the point in the current viewport
             int contentX = viewToContent((int) mLastTouchX + mScrollX);
             int contentY = viewToContent((int) mLastTouchY + mScrollY);
-            int left = nativeGetBlockLeftEdge(contentX, contentY);
+            int left = nativeGetBlockLeftEdge(contentX, contentY, mActualScale);
             if (left != NO_LEFTEDGE) {
                 // add a 5pt padding to the left edge. Re-calculate the zoom
                 // center so that the new scroll x will be on the left edge.
@@ -5656,5 +5658,5 @@ public class WebView extends AbsoluteLayout
     private native void     nativeUpdatePluginReceivesEvents();
     // return NO_LEFTEDGE means failure.
     private static final int NO_LEFTEDGE = -1;
-    private native int      nativeGetBlockLeftEdge(int x, int y);
+    private native int      nativeGetBlockLeftEdge(int x, int y, float scale);
 }

core/java/android/webkit/WebViewCore.java

@@ -648,6 +648,7 @@ final class WebViewCore {
     }
 
         static final String[] HandlerDebugString = {
+            "UPDATE_FRAME_CACHE_IF_LOADING", // = 98
             "SCROLL_TEXT_INPUT", // = 99
             "LOAD_URL", // = 100;
             "STOP_LOADING", // = 101;
@@ -699,6 +700,7 @@ final class WebViewCore {
 
     class EventHub {
         // Message Ids
+        static final int UPDATE_FRAME_CACHE_IF_LOADING = 98;
         static final int SCROLL_TEXT_INPUT = 99;
         static final int LOAD_URL = 100;
         static final int STOP_LOADING = 101;
@@ -805,10 +807,11 @@ final class WebViewCore {
                 @Override
                 public void handleMessage(Message msg) {
                     if (DebugFlags.WEB_VIEW_CORE) {
-                        Log.v(LOGTAG, (msg.what < SCROLL_TEXT_INPUT || msg.what
+                        Log.v(LOGTAG, (msg.what < UPDATE_FRAME_CACHE_IF_LOADING
+                                || msg.what
                                 > FREE_MEMORY ? Integer.toString(msg.what)
                                 : HandlerDebugString[msg.what
-                                        - SCROLL_TEXT_INPUT])
+                                        - UPDATE_FRAME_CACHE_IF_LOADING])
                                 + " arg1=" + msg.arg1 + " arg2=" + msg.arg2
                                 + " obj=" + msg.obj);
                     }
@@ -825,6 +828,10 @@ final class WebViewCore {
                             mNativeClass = 0;
                             break;
 
+                        case UPDATE_FRAME_CACHE_IF_LOADING:
+                            nativeUpdateFrameCacheIfLoading();
+                            break;
+
                         case SCROLL_TEXT_INPUT:
                             nativeScrollFocusedTextInput(msg.arg1, msg.arg2);
                             break;
@@ -1938,6 +1945,8 @@ final class WebViewCore {
                 WebView.CLEAR_TEXT_ENTRY).sendToTarget();
     }
 
+    private native void nativeUpdateFrameCacheIfLoading();
+
     /**
      * Scroll the focused textfield to (x, y) in document space
      */