Scroll while selecting

chrome/browser/resources/pdf/pdf.js

Index: chrome/browser/resources/pdf/pdf.js
diff --git a/chrome/browser/resources/pdf/pdf.js b/chrome/browser/resources/pdf/pdf.js
index 735c508fdd197c0924cf7b8127f5f9d6c0eb9ee0..4924cae8ddd33528baac3270f64f83d0c18de39d 100644
--- a/chrome/browser/resources/pdf/pdf.js
+++ b/chrome/browser/resources/pdf/pdf.js
@@ -408,9 +408,40 @@ PDFViewer.prototype = {
       case 'cancelStreamUrl':
         chrome.streamsPrivate.abort(this.streamDetails_.streamUrl);
         break;
+      case 'isSelecting':
+        if (message.data.isSelecting == this.isSelecting_)
+          break;
+        this.isSelecting_ = message.data.isSelecting_;
+        if (this.isSelecting_) {
+          this.plugin_.addEventListener('mousemove',
+                                        selectionDragListener,
+                                        false);
+        } else {
+          this.plugin_.removeEventListener('mousemove',
+                                           selectionDragListener,
+                                           false);
+        }
+        break;
     }
   },
 
+  getDragScrollVelocity_: function(pos, max_pos) {
+    // This gives a higher velocity as the pos approaches 0 or max_pos.
+    var velocity = Math.abs(ACCEL_COEFFICIENT * pos - (max_pos / 2));
+    // This gives a range in which there is no velocity for the given pos.
+    velocity -= DRAG_START_COEFFICIENT;
+    // Bound the velocity between 0 and MAX_VELOCITY.
+    velocity = Math.max(0, min(MAX_VELOCITY, velocity));
+  }
+
+  selectionDragListener_: function(event) {
+    var relative_x = event.x - this.plugin_.clientLeft;
+    var relative_y = event.y - this.plugin_.clientTop;
+    var x_velocity = this.getDragScrollVelocity_(relative_x, this.plugin_.width);
+    var y_velocity = this.getDragScrollVelocity_(relative_y, this.plugin_.height);
+    if (event.x )
+  },
+
   /**
    * @private
    * A callback that's called before the zoom changes. Notify the plugin to stop