Support minimum gesture bounds in GestureProvider

content/browser/renderer_host/input/motion_event_android.cc

Index: content/browser/renderer_host/input/motion_event_android.cc
diff --git a/content/browser/renderer_host/input/motion_event_android.cc b/content/browser/renderer_host/input/motion_event_android.cc
index c0f1721480eec0359c0b928d3516d983ceac0eb3..cf9c31fb3fcf760cf94b0aa0fc991aa410f5c11d 100644
--- a/content/browser/renderer_host/input/motion_event_android.cc
+++ b/content/browser/renderer_host/input/motion_event_android.cc
@@ -62,6 +62,18 @@ base::TimeTicks FromAndroidTime(int64 time_ms) {
   return base::TimeTicks() + base::TimeDelta::FromMilliseconds(time_ms);
 }
 
+float GetMinTouchMajorDipsForTool(int android_tool_type) {
+  switch (android_tool_type) {
+    case TOOL_TYPE_MOUSE:
+    case TOOL_TYPE_STYLUS:
+      return 0.f;
+    default:
+      // This value is somewhat arbitrarily chosen, but was used with success in
+      // the old gesture detection pipeline.
+      return 24.f;
+  };
+}
+
 }  // namespace
 
 MotionEventAndroid::MotionEventAndroid(float pix_to_dip,
@@ -79,13 +91,15 @@ MotionEventAndroid::MotionEventAndroid(float pix_to_dip,
                                        jint pointer_id_0,
                                        jint pointer_id_1,
                                        jfloat touch_major_0_pixels,
-                                       jfloat touch_major_1_pixels)
+                                       jfloat touch_major_1_pixels,
+                                       jint tool_type)
     : cached_time_(FromAndroidTime(time_ms)),
       cached_action_(FromAndroidAction(android_action)),
       cached_pointer_count_(pointer_count),
       cached_history_size_(history_size),
       cached_action_index_(action_index),
       pix_to_dip_(pix_to_dip),
+      min_touch_major_dips_(GetMinTouchMajorDipsForTool(tool_type)),
       should_recycle_(false) {
   DCHECK_GT(pointer_count, 0);
   DCHECK_GE(history_size, 0);
@@ -102,6 +116,7 @@ MotionEventAndroid::MotionEventAndroid(float pix_to_dip,
 }
 
 MotionEventAndroid::MotionEventAndroid(float pix_to_dip,
+                                       float min_touch_major_dips_,
                                        JNIEnv* env,
                                        jobject event)
     : cached_time_(FromAndroidTime(Java_MotionEvent_getEventTime(env, event))),
@@ -111,6 +126,7 @@ MotionEventAndroid::MotionEventAndroid(float pix_to_dip,
       cached_history_size_(Java_MotionEvent_getHistorySize(env, event)),
       cached_action_index_(Java_MotionEvent_getActionIndex(env, event)),
       pix_to_dip_(pix_to_dip),
+      min_touch_major_dips_(min_touch_major_dips_),
       should_recycle_(true) {
   event_.Reset(env, event);
   DCHECK(event_.obj());
@@ -138,6 +154,7 @@ MotionEventAndroid::MotionEventAndroid(const MotionEventAndroid& other)
       cached_history_size_(other.cached_history_size_),
       cached_action_index_(other.cached_action_index_),
       pix_to_dip_(other.pix_to_dip_),
+      min_touch_major_dips_(other.min_touch_major_dips_),
       should_recycle_(true) {
   DCHECK(event_.obj());
   for (size_t i = 0; i < MAX_POINTERS_TO_CACHE; ++i) {
@@ -191,11 +208,7 @@ float MotionEventAndroid::GetY(size_t pointer_index) const {
 }
 
 float MotionEventAndroid::GetTouchMajor(size_t pointer_index) const {
-  DCHECK_LT(pointer_index, cached_pointer_count_);
-  if (pointer_index < MAX_POINTERS_TO_CACHE)
-    return cached_touch_majors_[pointer_index];
-  return ToDips(Java_MotionEvent_getTouchMajorF_I(
-      AttachCurrentThread(), event_.obj(), pointer_index));
+  return std::max(min_touch_major_dips_, GetRawTouchMajor(pointer_index));
 }
 
 float MotionEventAndroid::GetPressure(size_t pointer_index) const {
@@ -221,8 +234,12 @@ base::TimeTicks MotionEventAndroid::GetHistoricalEventTime(
 float MotionEventAndroid::GetHistoricalTouchMajor(
     size_t pointer_index,
     size_t historical_index) const {
-  return ToDips(Java_MotionEvent_getHistoricalTouchMajorF_I_I(
-      AttachCurrentThread(), event_.obj(), pointer_index, historical_index));
+  return std::max(min_touch_major_dips_,
+                  ToDips(Java_MotionEvent_getHistoricalTouchMajorF_I_I(
+                      AttachCurrentThread(),
+                      event_.obj(),
+                      pointer_index,
+                      historical_index)));
 }
 
 float MotionEventAndroid::GetHistoricalX(size_t pointer_index,
@@ -248,6 +265,7 @@ scoped_ptr<ui::MotionEvent> MotionEventAndroid::Cancel() const {
       gfx::ScalePoint(cached_positions_[0], 1.f / pix_to_dip_);
   return scoped_ptr<MotionEvent>(
       new MotionEventAndroid(pix_to_dip_,
+                             min_touch_major_dips_,
                              AttachCurrentThread(),
                              Obtain(GetDownTime(),
                                     GetEventTime(),
@@ -256,7 +274,15 @@ scoped_ptr<ui::MotionEvent> MotionEventAndroid::Cancel() const {
                                     position_pixels.y()).obj()));
 }
 
-float MotionEventAndroid::GetTouchMinor(size_t pointer_index) const {
+float MotionEventAndroid::GetRawTouchMajor(size_t pointer_index) const {
+  DCHECK_LT(pointer_index, cached_pointer_count_);
+  if (pointer_index < MAX_POINTERS_TO_CACHE)
+    return cached_touch_majors_[pointer_index];
+  return ToDips(Java_MotionEvent_getTouchMajorF_I(
+      AttachCurrentThread(), event_.obj(), pointer_index));
+}
+
+float MotionEventAndroid::GetRawTouchMinor(size_t pointer_index) const {
   return ToDips(Java_MotionEvent_getTouchMinorF_I(
       AttachCurrentThread(), event_.obj(), pointer_index));
 }