Addressing text selection mode on Android and AccessibilityEvent discrepancies

This CL addresses various coupled bugs in both text selection and non-
default granularity navigation for input fields/contenteditables on
Android. It fixes various issues with improper announcements,
announcements at the wrong time, and text selection not functioning in
general. It also addresses AccessibilityEvent discrepancies under-the-
hood in cases where we appeared to have the correct functionality to
the user, but only by happenstance as we were passing bad data to
TalkBack.

This CL addresses:
Bug 1041649 - Text selection on Android broken/not functioning
Bug 1017466 - Contenteditable word granularity navigation not reading
correctly
Bug 1041587 - Beginning/End of field announcements being read at
wrong index

Bug: 1041649,1017466,1041587
Change-Id: I30a8888e99e90356398d14319fbdf225839f5dac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1998829
Commit-Queue: Mark Schillaci <mschillaci@google.com>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734171}

content/browser/accessibility/android_granularity_movement_browsertest.cc

@@ -85,8 +85,7 @@ class AndroidGranularityMovementBrowserTest : public ContentBrowserTest {
     int previous_end_index = -1;
     while (manager->NextAtGranularity(granularity, end_index, android_node,
                                       &start_index, &end_index)) {
-      int len =
-          (granularity == GRANULARITY_CHARACTER) ? 1 : end_index - start_index;
+      int len = end_index - start_index;
       base::string16 selection = text.substr(start_index, len);
       if (base::EndsWith(selection, base::ASCIIToUTF16("\n"),
                          base::CompareCase::INSENSITIVE_ASCII))
@@ -111,8 +110,7 @@ class AndroidGranularityMovementBrowserTest : public ContentBrowserTest {
     start_index = end_index;
     while (manager->PreviousAtGranularity(
         granularity, start_index, android_node, &start_index, &end_index)) {
-      int len =
-          (granularity == GRANULARITY_CHARACTER) ? 1 : end_index - start_index;
+      int len = end_index - start_index;
       base::string16 selection = text.substr(start_index, len);
       if (base::EndsWith(selection, base::ASCIIToUTF16("\n"),
                          base::CompareCase::INSENSITIVE_ASCII))

content/browser/accessibility/browser_accessibility_manager_android.cc

@@ -287,8 +287,9 @@ bool BrowserAccessibilityManagerAndroid::NextAtGranularity(
       base::i18n::UTF16CharIterator iter(text.data(), text.size());
       while (!iter.end() && iter.array_pos() <= cursor_index)
         iter.Advance();
-      *start_index = iter.array_pos();
       *end_index = iter.array_pos();
+      iter.Rewind();
+      *start_index = iter.array_pos();
       break;
     }
     case ANDROID_ACCESSIBILITY_NODE_INFO_MOVEMENT_GRANULARITY_WORD:
@@ -335,7 +336,7 @@ bool BrowserAccessibilityManagerAndroid::PreviousAtGranularity(
         iter.Advance();
       }
       *start_index = previous_index;
-      *end_index = previous_index;
+      *end_index = iter.array_pos();
       break;
     }
     case ANDROID_ACCESSIBILITY_NODE_INFO_MOVEMENT_GRANULARITY_WORD:

content/browser/accessibility/web_contents_accessibility_android.cc

@@ -1066,9 +1066,9 @@ jboolean WebContentsAccessibilityAndroid::NextAtGranularity(
   if (root_manager_->NextAtGranularity(granularity, cursor_index, node,
                                        &start_index, &end_index)) {
     base::string16 text = node->GetInnerText();
-    Java_WebContentsAccessibilityImpl_finishGranularityMove(
+    Java_WebContentsAccessibilityImpl_finishGranularityMoveNext(
         env, obj, base::android::ConvertUTF16ToJavaString(env, text),
-        extend_selection, start_index, end_index, true);
+        extend_selection, start_index, end_index);
     return true;
   }
   return false;
@@ -1132,10 +1132,10 @@ jboolean WebContentsAccessibilityAndroid::PreviousAtGranularity(
   int end_index = -1;
   if (root_manager_->PreviousAtGranularity(granularity, cursor_index, node,
                                            &start_index, &end_index)) {
-    Java_WebContentsAccessibilityImpl_finishGranularityMove(
+    Java_WebContentsAccessibilityImpl_finishGranularityMovePrevious(
         env, obj,
         base::android::ConvertUTF16ToJavaString(env, node->GetInnerText()),
-        extend_selection, start_index, end_index, false);
+        extend_selection, start_index, end_index);
     return true;
   }
   return false;

content/browser/accessibility/web_contents_accessibility_android.h

@@ -137,8 +137,8 @@ class CONTENT_EXPORT WebContentsAccessibilityAndroid
   // of our own selection in BrowserAccessibilityManager.java for static
   // text, but if this is an editable text node, updates the selected text
   // in Blink, too, and either way calls
-  // Java_BrowserAccessibilityManager_finishGranularityMove with the
-  // result.
+  // Java_BrowserAccessibilityManager_finishGranularityMove[NEXT/PREVIOUS]
+  // with the result.
   jboolean NextAtGranularity(JNIEnv* env,
                              const base::android::JavaParamRef<jobject>& obj,
                              jint granularity,