Bug 1073457 - Launch long tap detector when APZ isn't enabled. f=mtseng, r=roc

LaunchLongTapDetector() is used to fire long tap to select word when
async pan zoom is not enabled. We should check if async pan zoom is
enabled rather than check whether it's on main process.

This can also fix selection carets not working on e10s.

layout/base/SelectionCarets.cpp

@@ -83,7 +83,7 @@ SelectionCarets::SelectionCarets(nsIPresShell* aPresShell)
   , mActiveTouchId(-1)
   , mCaretCenterToDownPointOffsetY(0)
   , mDragMode(NONE)
-  , mAPZenabled(false)
+  , mAsyncPanZoomEnabled(false)
   , mEndCaretVisible(false)
   , mStartCaretVisible(false)
   , mVisible(false)
@@ -119,6 +119,9 @@ SelectionCarets::Init()
     return;
   }
 
+  docShell->GetAsyncPanZoomEnabled(&mAsyncPanZoomEnabled);
+  mAsyncPanZoomEnabled = mAsyncPanZoomEnabled && gfxPrefs::AsyncPanZoomEnabled();
+
   docShell->AddWeakReflowObserver(this);
   docShell->AddWeakScrollObserver(this);
 }
@@ -1014,9 +1017,6 @@ DispatchScrollViewChangeEvent(nsIPresShell *aPresShell, const dom::ScrollState a
 void
 SelectionCarets::AsyncPanZoomStarted(const mozilla::CSSIntPoint aScrollPos)
 {
-  // Receives the notifications from AsyncPanZoom, sets mAPZenabled as true here
-  // to bypass the notifications from ScrollPositionChanged callbacks
-  mAPZenabled = true;
   SetVisibility(false);
 
   SELECTIONCARETS_LOG("Dispatch scroll started with position x=%d, y=%d",
@@ -1037,7 +1037,7 @@ SelectionCarets::AsyncPanZoomStopped(const mozilla::CSSIntPoint aScrollPos)
 void
 SelectionCarets::ScrollPositionChanged()
 {
-  if (!mAPZenabled && mVisible) {
+  if (!mAsyncPanZoomEnabled && mVisible) {
     SetVisibility(false);
     //TODO: handling scrolling for selection bubble when APZ is off
 
@@ -1049,7 +1049,7 @@ SelectionCarets::ScrollPositionChanged()
 void
 SelectionCarets::LaunchLongTapDetector()
 {
-  if (XRE_GetProcessType() != GeckoProcessType_Default) {
+  if (mAsyncPanZoomEnabled) {
     return;
   }
 
@@ -1071,7 +1071,7 @@ SelectionCarets::LaunchLongTapDetector()
 void
 SelectionCarets::CancelLongTapDetector()
 {
-  if (XRE_GetProcessType() != GeckoProcessType_Default) {
+  if (mAsyncPanZoomEnabled) {
     return;
   }
 

layout/base/SelectionCarets.h

@@ -227,7 +227,8 @@ private:
   DragMode mDragMode;
 
   // True if AsyncPanZoom is enabled
-  bool mAPZenabled;
+  bool mAsyncPanZoomEnabled;
+
   bool mEndCaretVisible;
   bool mStartCaretVisible;
   bool mVisible;