Convert all synthetic gesture coordinates from CSS pixels to DIPs.

There is currently some inconsistency about the units of pixels being passed to
synthetic gestures, some are CSS pixels and some are density independent pixels
(DIPs). The internal classes expect DIPs but the scroll distance is being
passed in CSS pixels, causing us to scroll too far on pages with page scale
factors > 1.

This patch clarifies the interface between the JS functions for gestures and the
internal classes. The JS functions expect coordinates to be in CSS pixels which
are then converted to DIPs before being passed to the gesture objects.

BUG=313669

Review URL: https://codereview.chromium.org/56093002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233677 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 12 insertions, 8 deletions

diff --git a/content/renderer/gpu/gpu_benchmarking_extension.cc b/content/renderer/gpu/gpu_benchmarking_extension.cc
index 7acb6c6..f8365dc 100644
--- a/content/renderer/gpu/gpu_benchmarking_extension.cc
+++ b/content/renderer/gpu/gpu_benchmarking_extension.cc
@@ -482,7 +482,10 @@ class GpuBenchmarkingWrapper : public v8::Extension {
                                callback_local,
                                context.web_frame()->mainWorldScriptContext());
 
-    int pixels_to_scroll = args[2]->IntegerValue();
+    // Convert coordinates from CSS pixels to density independent pixels (DIPs).
+    float page_scale_factor = context.web_view()->pageScaleFactor();
+
+    int pixels_to_scroll = args[2]->IntegerValue() * page_scale_factor;
 
     int mouse_event_x = 0;
     int mouse_event_y = 0;
@@ -499,10 +502,8 @@ class GpuBenchmarkingWrapper : public v8::Extension {
         return;
       }
 
-      mouse_event_x = args[3]->IntegerValue() *
-          context.web_view()->pageScaleFactor();
-      mouse_event_y = args[4]->IntegerValue() *
-          context.web_view()->pageScaleFactor();
+      mouse_event_x = args[3]->IntegerValue() * page_scale_factor;
+      mouse_event_y = args[4]->IntegerValue() * page_scale_factor;
     }
 
     // TODO(nduca): If the render_view_impl is destroyed while the gesture is in
@@ -536,10 +537,13 @@ class GpuBenchmarkingWrapper : public v8::Extension {
       return;
     }
 
+    // Convert coordinates from CSS pixels to density independent pixels (DIPs).
+    float page_scale_factor = context.web_view()->pageScaleFactor();
+
     bool zoom_in = args[0]->BooleanValue();
-    int pixels_to_move = args[1]->IntegerValue();
-    int anchor_x = args[2]->IntegerValue();
-    int anchor_y = args[3]->IntegerValue();
+    int pixels_to_move = args[1]->IntegerValue() * page_scale_factor;
+    int anchor_x = args[2]->IntegerValue() * page_scale_factor;
+    int anchor_y = args[3]->IntegerValue() * page_scale_factor;
 
     v8::Local<v8::Function> callback_local =
         v8::Local<v8::Function>::Cast(args[4]);