Revert 181950 - Broke content_unittests on Android

> Distribute extra memory evenly among visible clients
> 
> After computing all clients' memory budgets, take any
> extra memory left over and distribute it amongst the
> visible clients (so that, if their memory requirments
> suddenly jump, they don't need to wait for a roundtrip
> to the GPU process to get extra memory).
> 
> Disallow keeping around backgrounded tabs' contents on
> Android, to keep the maximum for the main tab.
> 
> Explicitly limit the memory to use for prepainting by
> specifying NiceToHave on Mac to avoid performance problems.
> 
> BUG=175125
> 
> Review URL: https://codereview.chromium.org/12226082

TBR=ccameron@chromium.org
Review URL: https://codereview.chromium.org/12208134

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@181962 0039d316-1c4b-4281-b951-d872f2087c98

content/common/gpu/gpu_memory_manager.cc

@@ -531,9 +531,6 @@ uint64 GpuMemoryManager::ComputeCap(
   size_t bytes_size = bytes.size();
   uint64 bytes_sum = 0;
 
-  if (bytes_size == 0)
-    return std::numeric_limits<uint64>::max();
-
   // Sort and add up all entries
   std::sort(bytes.begin(), bytes.end());
   for (size_t i = 0; i < bytes_size; ++i)
@@ -745,11 +742,6 @@ void GpuMemoryManager::ComputeNonvisibleSurfacesAllocationsNonuniform() {
         bytes_available_total - bytes_allocated_visible);
   }
 
-  // On Android, always discard everything that is nonvisible.
-#if defined(OS_ANDROID)
-  bytes_available_nonvisible = 0;
-#endif
-
   // Determine which now-visible clients should keep their contents when
   // they are made nonvisible.
   for (ClientStateList::const_iterator it = clients_visible_mru_.begin();
@@ -799,58 +791,11 @@ void GpuMemoryManager::ComputeNonvisibleSurfacesAllocationsNonuniform() {
   }
 }
 
-void GpuMemoryManager::DistributeRemainingMemoryToVisibleSurfaces() {
-  uint64 bytes_available_total = GetAvailableGpuMemory();
-  uint64 bytes_allocated_total = 0;
-
-  for (ClientStateList::const_iterator it = clients_visible_mru_.begin();
-       it != clients_visible_mru_.end();
-       ++it) {
-    GpuMemoryManagerClientState* client_state = *it;
-    bytes_allocated_total += client_state->bytes_allocation_when_visible_;
-  }
-  for (ClientStateList::const_iterator it = clients_nonvisible_mru_.begin();
-       it != clients_nonvisible_mru_.end();
-       ++it) {
-    GpuMemoryManagerClientState* client_state = *it;
-    bytes_allocated_total += client_state->bytes_allocation_when_nonvisible_;
-  }
-
-  if (bytes_allocated_total >= bytes_available_total)
-    return;
-
-  std::vector<uint64> bytes_extra_requests;
-  for (ClientStateList::const_iterator it = clients_visible_mru_.begin();
-       it != clients_visible_mru_.end();
-       ++it) {
-    GpuMemoryManagerClientState* client_state = *it;
-    CHECK(GetMaximumClientAllocation() >=
-          client_state->bytes_allocation_when_visible_);
-    uint64 bytes_extra = GetMaximumClientAllocation() -
-                         client_state->bytes_allocation_when_visible_;
-    bytes_extra_requests.push_back(bytes_extra);
-  }
-  uint64 bytes_extra_cap = ComputeCap(
-      bytes_extra_requests, bytes_available_total - bytes_allocated_total);
-  for (ClientStateList::const_iterator it = clients_visible_mru_.begin();
-       it != clients_visible_mru_.end();
-       ++it) {
-    GpuMemoryManagerClientState* client_state = *it;
-    uint64 bytes_extra = GetMaximumClientAllocation() -
-                         client_state->bytes_allocation_when_visible_;
-    client_state->bytes_allocation_when_visible_ += std::min(
-        bytes_extra, bytes_extra_cap);
-  }
-}
-
 void GpuMemoryManager::AssignSurfacesAllocationsNonuniform() {
   // Compute allocation when for all clients.
   ComputeVisibleSurfacesAllocationsNonuniform();
   ComputeNonvisibleSurfacesAllocationsNonuniform();
 
-  // Distribute the remaining memory to visible clients.
-  DistributeRemainingMemoryToVisibleSurfaces();
-
   // Send that allocation to the clients.
   ClientStateList clients = clients_visible_mru_;
   clients.insert(clients.end(),
@@ -877,11 +822,7 @@ void GpuMemoryManager::AssignSurfacesAllocationsNonuniform() {
     allocation.renderer_allocation.bytes_limit_when_visible =
         client_state->bytes_allocation_when_visible_;
     allocation.renderer_allocation.priority_cutoff_when_visible =
-#if defined(OS_MACOSX)
-        GpuMemoryAllocationForRenderer::kPriorityCutoffAllowNiceToHave;
-#else
         GpuMemoryAllocationForRenderer::kPriorityCutoffAllowEverything;
-#endif
 
     allocation.renderer_allocation.bytes_limit_when_not_visible =
         client_state->bytes_allocation_when_nonvisible_;

content/common/gpu/gpu_memory_manager.h

@@ -124,7 +124,6 @@ class CONTENT_EXPORT GpuMemoryManager :
   // Compute the allocation for clients when visible and not visible.
   void ComputeVisibleSurfacesAllocationsNonuniform();
   void ComputeNonvisibleSurfacesAllocationsNonuniform();
-  void DistributeRemainingMemoryToVisibleSurfaces();
 
   // Compute the budget for a client. Allow at most bytes_above_required_cap
   // bytes above client_state's required level. Allow at most

content/common/gpu/gpu_memory_manager_unittest.cc

@@ -924,6 +924,7 @@ TEST_F(GpuMemoryManagerTestNonuniform, BackgroundMru) {
   EXPECT_GE(stub3.BytesWhenVisible(), 23u);
   EXPECT_LT(stub1.BytesWhenVisible(), 32u);
   EXPECT_LT(stub2.BytesWhenVisible(), 32u);
+  EXPECT_LT(stub3.BytesWhenVisible(), 32u);
   EXPECT_GE(stub1.BytesWhenNotVisible(), 6u);
   EXPECT_GE(stub2.BytesWhenNotVisible(), 6u);
   EXPECT_GE(stub3.BytesWhenNotVisible(), 6u);
@@ -1040,10 +1041,10 @@ TEST_F(GpuMemoryManagerTestNonuniform, DefaultAllocation) {
 
   FakeClient stub1(&memmgr_, GenerateUniqueSurfaceId(), true);
 
-  // Expect that a client which has not sent stats receive at
-  // least the default allocation.
+  // Expect that a client which has not sent stats receive the
+  // default allocation.
   Manage();
-  EXPECT_GE(stub1.BytesWhenVisible(),
+  EXPECT_EQ(stub1.BytesWhenVisible(),
             memmgr_.GetDefaultClientAllocation());
   EXPECT_EQ(stub1.BytesWhenNotVisible(), 0u);
 }