Don't send DidChangeView to the plugin unless the parameters have actually changed.

webkit/plugins/ppapi/ppapi_plugin_instance.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
@@ skipping 199 matching lines @@
 PluginInstance::PluginInstance(
     PluginDelegate* delegate,
     PluginModule* module,
     ::ppapi::PPP_Instance_Combined* instance_interface)
     : delegate_(delegate),
       module_(module),
       instance_interface_(instance_interface),
       pp_instance_(0),
       container_(NULL),
       full_frame_(false),
+      sent_did_change_view_(false),
       has_webkit_focus_(false),
       has_content_area_focus_(false),
       find_identifier_(-1),
       plugin_find_interface_(NULL),
       plugin_messaging_interface_(NULL),
       plugin_input_event_interface_(NULL),
       plugin_private_interface_(NULL),
       plugin_pdf_interface_(NULL),
       plugin_policy_updated_interface_(NULL),
       plugin_selection_interface_(NULL),
@@ skipping 268 matching lines @@
 
   // If the plugin supports the private instance interface, try to retrieve its
   // instance object.
   if (LoadPrivateInterface())
     return plugin_private_interface_->GetInstanceObject(pp_instance());
   return PP_MakeUndefined();
 }
 
 void PluginInstance::ViewChanged(const gfx::Rect& position,
                                  const gfx::Rect& clip) {
+  // WebKit can give weird (x,y) positions for empty clip rects (since the
+  // position technically doesn't matter). But we want to make these
+  // consistent since this is given to the plugin, so force everything to 0
+  // in the "everything is clipped" case.
+  gfx::Rect new_clip;
+  if (!clip.IsEmpty())
+    new_clip = clip;
+
+  // Don't notify the plugin if we've already sent these same params before.
+  if (sent_did_change_view_ && position == position_ && new_clip == clip_)
+    return;
+
+  sent_did_change_view_ = true;
+  position_ = position;
+  clip_ = new_clip;
   fullscreen_ = (fullscreen_container_ != NULL);
-  position_ = position;
-
-  if (clip.IsEmpty()) {
-    // WebKit can give weird (x,y) positions for empty clip rects (since the
-    // position technically doesn't matter). But we want to make these
-    // consistent since this is given to the plugin, so force everything to 0
-    // in the "everything is clipped" case.
-    clip_ = gfx::Rect();
-  } else {
-    clip_ = clip;
-  }
 
   PP_Rect pp_position, pp_clip;
   RectToPPRect(position_, &pp_position);
   RectToPPRect(clip_, &pp_clip);
   instance_interface_->DidChangeView(pp_instance(), &pp_position, &pp_clip);
 }
 
 void PluginInstance::SetWebKitFocus(bool has_focus) {
   if (has_webkit_focus_ == has_focus)
     return;
@@ skipping 1021 matching lines @@
 }
 
 void PluginInstance::DoSetCursor(WebCursorInfo* cursor) {
   cursor_.reset(cursor);
   if (fullscreen_container_)
     fullscreen_container_->DidChangeCursor(*cursor);
 }
 
 }  // namespace ppapi
 }  // namespace webkit