Adds selection expansion support for Contextual Search.

chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java

Index: chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java b/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java
index 4304435e777a360eabb4d214c071fc7926aa80cd..606d9d217bfc671b3586c424992dab308d1dcc74 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchSelectionController.java
@@ -46,6 +46,7 @@ public class ContextualSearchSelectionController {
     private boolean mIsSelectionBeingModified;
     private boolean mWasLastTapValid;
     private boolean mIsWaitingForInvalidTapDetection;
+    private boolean mDidAdjustSelection;

[pedro (no code reviews), 2015/06/25 01:30:28]

Nit: mDidAdjustSelection --> mDidExpandSelection

[aurimas (slooooooooow), 2015/07/01 00:45:38]

Done

 
     private float mX;
     private float mY;
@@ -129,6 +130,11 @@ public class ContextualSearchSelectionController {
      * @param selection The selection portion of the context.
      */
     void handleSelectionChanged(String selection) {
+        if (mDidAdjustSelection) {
+            mDidAdjustSelection = false;
+            return;
+        }
+
         if (selection == null || selection.isEmpty()) {
             scheduleInvalidTapNotification();
             // When the user taps on the page it will place the caret in that position, which
@@ -249,6 +255,19 @@ public class ContextualSearchSelectionController {
     }
 
     /**
+     * Adjusts the current selection by the given amounts.
+     */
+    void adjustSelection(int selectionStartAdjust, int selectionEndAdjust) {

[David Trainor- moved to gerrit, 2015/06/25 00:34:55]

Eh might as well flesh out this javadoc with the same strings as above.  Should
we also make sure selectionStartAdjust and selectionEndAdjust aren't both 0 (I'm
assuming they're both offsets from the current selection points)?  I'm imagining
that doing weird things with the early out above if the user tries to refine the
selection.

+        // TODO(donnd): add code to verify that the selection is still valid before changing it!
+        ContentViewCore basePageContentView = getBaseContentView();
+        if (basePageContentView != null) {

[pedro (no code reviews), 2015/06/25 01:30:28]

Probably it's worth checking that basePageContentView.getWebContents() is also
not null

[aurimas (slooooooooow), 2015/07/01 00:45:38]

Done

+            mDidAdjustSelection = true;
+            basePageContentView.getWebContents().moveSelectionByCharacterOffset(
+                    selectionStartAdjust, selectionEndAdjust);
+        }
+    }
+
+    /**
      * @return whether a tap at the given coordinates should be handled or not.
      */
     private boolean shouldHandleTap(int x, int y) {